Source: UNIVERSITY OF CALIFORNIA, DAVIS submitted to
IMPROVING FOOD QUALITY AND HUMAN HEALTH THROUGH DIETARY LACTIC ACID BACTERIA
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1005041
Grant No.
(N/A)
Project No.
CA-D-FST-2093-H
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Jan 26, 2015
Project End Date
Sep 30, 2019
Grant Year
(N/A)
Project Director
Marco, MA.
Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671
Performing Department
Food Science and Technology
Non Technical Summary
The microbial composition of foods and beverages is strongly linked to human health and well-being. This is evident during food-borne outbreaks caused by the entry of human pathogens into food supply chains. Conversely, growth of certain types of bacteria in food matrices is essential for the production of fermented products such yogurt, cheese, olives, and sausage or for delivery as probiotics intended to improve health. These two opposing (detrimental and beneficial) facets of microorganisms in foods are important to food industries in California that want to ensure their products are safe, appealing, and provide optimal health benefits. Presently, we have an incomplete understanding of how to fully control the microorganisms associated with food environments. This project will investigate the integral roles of lactic acid bacteria (LAB) in food and gut ecosystems that are important to maintaining healthy, safe, and tasty food supplies. Model LAB strains will be investigated for their ecology and functional attributes on fresh and fermented foods as well as in mammalian digestive tracts. The project will elucidate general LAB adaptations for growth and survival in plant and dairy foods, identify the functional traits of LAB useful for improved control and efficiency in food fermentations and prevention of foodborne pathogen contamination and growth, and optimize the efficacy of probiotic LAB for the promotion of human health.
Animal Health Component
0%
Research Effort Categories
Basic
50%
Applied
30%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5024010110030%
5034099107020%
7124010110020%
7024010104030%
Knowledge Area
702 - Requirements and Function of Nutrients and Other Food Components; 712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins; 503 - Quality Maintenance in Storing and Marketing Food Products; 502 - New and Improved Food Products;

Subject Of Investigation
4099 - Microorganisms, general/other; 4010 - Bacteria;

Field Of Science
1040 - Molecular biology; 1070 - Ecology; 1100 - Bacteriology;
Goals / Objectives
The goal of this project is to improve food supplies and human health through and improved understanding of the genetic and metabolic diversity of lactic acid bacteria. This will be achieved through the following objectives: (i) Perform molecular genetic analysis on model LAB strains (Lactococcus lactis KF147 and Lactobacillus casei BL23) to identify plant and milk-specific phenotypes; (ii) validate the mechanisms by which certain model LAB strains (Lactobacillus plantarum WCFS1 and Weisella confusa TRW1) are beneficial in olive fermentations; (iii) determine the contributions of host diet to probiotic Lactobacillus survival and probiotic effects in the mammalian gut.
Project Methods
This project will employ standard and advanced methods of microbial analysis. Specifically, we will employ culture-dependent and -independent bacterial detection and enumeration techniques. We will use high-throughput DNA sequencing methods as well as (meta)transcriptomic, proteomic, and metabolomic methods to examine microbial communities and individual lactic acid bacteria (LAB) strains in food systems and the mammalian digestive tracts. Results will be analyzed and evaluated through the application of bioinformatics and statistical methods to guide interpretation. The results will be ultimately used to guide changes in knowledge, actions, or conditionsto food and agricultural industries in California. The success of the efforts will be determined by direct contact and evaluation of our progress with those industries.

Progress 01/26/15 to 09/30/19

Outputs
Target Audience:The food system is worldwide. However, the US and California agricultural, biotechnology, biomedical, and food industries remain primary our target audiences for this research. Probiotics, food fermentation, and minimizing food pathogens is a primary effort of these industries to maintain a safe food supply and to enhance human health. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project provided training to postdoctoral scientists (Dr. Wenting Ju, Dr. Zhangyuan Zhai, Dr. Mary Moore, Dr. Sandra Appelt, Dr. Kanika Chauhan), graduate students (Benjamin Golomb, ZDustin Heeney, Zhengyao Xue, Eric Stevens, and Xiaochen Yin), technicians (Jose Zaragoza, Brendan McCarthy-Sinclair, and Jason Brooks), and undergraduate student interns. Training to Dustin Heeney, Zhengyao Xue, Ben Golomb and Xiaochen Yin were also provided during an industry internship. The individuals on the project received training from Dr. Marco on lactic acid bacteria and gut microbiology, HTP DNA sequencing microbial diversity analysis, and mechanisms of intestinal inflammation. These individuals are responsible for conducting animal and bacteriology experiments well as analyzing results in cooperation with Dr. Marco. How have the results been disseminated to communities of interest?Dissemination events include conference presentations, published journal articles, and consultations with local and international food processors and members of the media. Dissemination of knowledge beyond a scientific audience has included on-site tours of the research laboratory and description of the research program to university students, international visitors, casual visitors to the university (members of the public) and stakeholders (representing industrial sectors related to food science, nutrition, and health). What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Accomplishments during this period encompass publications and outreach aimed at disseminating knowledge on lactic acid bacteria (LAB). This past year's efforts mainly resulted in publications on Objective 1 and Objective 2. We published our findings on dairy-associated ecosystems. These findings pertain to the development of rapid diagnostics for the detection of bacterial pathogens that cause bovine mastitis. Rapid detection of those pathogens is a major advance for dairy farmers for supporting their efforts to prevent infection and spread of the infectious pathogens throughout the herd. LAB driven fermentations of dairy foods benefits benefit from research aimed at maintaining milk quality. Related to this topic was our investigation on the bacterial contents of milk during processing. As expected, a variety of LAB and other bacterial species were present. Remarkably, certain species were enriched during pasteurization and exhibited time-dependent shifts. Related to Objective 2 was our work to prevent pathogen contamination and maintain the expected quality of plant foods. LAB are members of olives and leafy green microbiomes and are integral to understanding how pathogenic E. coli could persist on some but not all plants in the field. Invited presentations covered all objectives. Results from this work and my other ongoing research pertaining to (model) LAB and their interactions with food and gut microbiomes were presented at numerous international conferences at various sites around the country and attended by industry, academics and the lay-public.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Sandra Appelt, Sharif S. Aly, Karen Tonooka, Kathy Glenn, Zhengyao Xue, Terry W. Lehenbauer, and Maria L. Marco. 2019. Development and comparison of LAMP and qPCR assays for the detection of Mycoplasma bovis in milk. Journal of Dairy Science 102(3): 1985-1996.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Zhengyao Xue and Maria L Marco. Accurate monitoring of living and total bacterial populations in milk to predict cheese defects. Jiangnan University Conference, Wuxi, China (November 14, 2018).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Mary E. Kable, Yanin Srisengfa, Zhengyao Xue, Laurynne C. Coates and Maria L. Marco. Bacterial population dynamics in raw and processed milk. 15th international symposium on milk genomics and human health (November 13-15, 2018).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Zhengyao Xue, Zachary Quart, Mary Kable and Maria L. Marco. Accurate monitoring of living and total bacterial populations in milk to predict cheese defects. 15th international symposium on milk genomics and human health (November 13-15, 2018).
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Mary E. Kable, Yanin Srisengfa, Zhengyao Xue, Laurynne C. Coates, and Maria L. Marco. 2019. Viable and total bacterial populations undergo equipment- and time-dependent shifts during milk processing. Applied Environmental Microbiology. 85:e00270-19.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Myrna Cadena, Todd Kelman, Maria L. Marco, and Maurice Pitesky. 2019. Understanding Antimicrobial Resistance (AMR) Profiles of Salmonella biofilms challenged with disinfectants commonly used during poultry processing. Foods. 8(7).
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Anne-laure Moyne, Tyann Blessington, Thomas R. Williams, Steven T. Koike, Michael D. Cahn, Maria L. Marco, Linda J. Harris. 2019. Conditions at the time of inoculation influence survival of attenuated Escherichia coli O157:H7 on field-inoculated lettuce. Food Microbiology 85(103274).


Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The food system is worldwide. However, the US and California agricultural, biotechnology, biomedical, and food industries remain primary our target audiences for this research. Probiotics, food fermentation, and minimizing food pathogens is a primary effort of these industries to maintain a safe food supply and to enhance human health. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training to postdoctoral scientists (Dr. Wenting Ju, Dr. Zhangyuan Zhai, Dr. Mary Moore, Dr. Sandra Appelt, Dr. Kanika Chauhan), graduate students (Benjamin Golomb, Zachary Bendiks, Dustin Heeney, Zhengyao Xue, Eric Stevens, and Xiaochen Yin), technicians (Jose Zaragoza, Brendan McCarthy-Sinclair, and Jason Brooks), and undergraduate student interns. Training to Ben Golomb and Xiaochen Yin were also provided during an industry internship. The individuals on the project received training from Dr. Marco on lactic acid bacteria and gut microbiology, HTP DNA sequencing microbial diversity analysis, and mechanisms of intestinal inflammation. These individuals are responsible for conducting animal and bacteriology experiments well as analyzing results in cooperation with Dr. Marco. How have the results been disseminated to communities of interest?Dissemination events include conference presentations, published journal articles, and consultations with local and international food processors and members of the media. Dissemination of knowledge beyond a scientific audience has included on-site tours of the research laboratory and description of the research program to university students, international visitors, casual visitors to the university (members of the public) and stakeholders (representing industrial sectors related to food science, nutrition, and health). What do you plan to do during the next reporting period to accomplish the goals?Activities for the next reporting period encompass the further development of all three objectives to achieve the goals of the project. For objective 1, we will continue investigations on the food microbiomes as they pertain to the function of model LAB in those food environments. We will also continue our on-going investigations on the mechanisms by which selected strains of LAB provide benefits to olive fermentations. Model strains (e.g. Lplantarum NCIBM8826 (WCFS1)) will be used for this research. Lastly, efforts will be made to deepen our analysis of host-diet effects on the intestinal microbiome, with particular regard to intestinal Lactobacillus. Dissemination of the results will be through published articles in peer-reviewed journals, a PhD thesis, direct meetings with industrial stakeholders, and communications to the press and the public.

Impacts
What was accomplished under these goals? Accomplishments during this period encompass publications and outreach efforts aimed at disseminating knowledge on lactic acid bacteria (LAB). This past year's efforts resulted in publications in Objective 3. Specifically, I reported on the impact of dietary sucrose on L. plantarum intestinal survival and effects on gut microbiome composition. I also published a paper on the impact of consuming L. plantarum in the context of a high fat diet and how this organism might be useful to improve the health of obese populations. A patent application was submitted with direct relevance to objectives 2 and 3. Invited presentations covered all objectives, but particularly emphasized objectives 1 and 3. Results from this work and my other ongoing research pertaining to (model) lactic acid bacteria and their interactions with food and gut microbiomes were presented at numerous international conferences at various sites around the country and attended by industry, academics and the lay-public.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Xiaochen Yin, Dustin D. Heeney, Yanin Tab Srisengfa, Shin-Yu Chen, Carolyn M. Slupsky, and Maria L. Marco. 2018. Sucrose metabolism alters Lactobacillus plantarum survival and interactions with the microbiota in the digestive tract. FEMS Microbiology Ecology 94(7)
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Alice Martinic, Javad Barouei, Zach Bendiks, Darya Mishchuk, Dustin Heeney, Roy Martin, Maria L Marco, and Carolyn M Slupsky. 2018. Supplementation of Lactobacillus plantarum in the context of a high fat diet improves intestinal barrier function and systemic metabolism. Journal of Proteome Research. 17(2790-2802).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Invited speaker. Title: Millions of microbes! San Francisco Exploratorium. October 11, 2018
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Invited speaker. Title: Connectivity between diet, probiotic Lactobacillus, and human health. MicroMeNu Conference. September 6, 2018
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Invited Speaker. Millions of Microbes. 3rd International Symposium on Fermented Foods and Beverages. July 19, 2018.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:The food system is worldwide. However, the US and California agricultural, biotechnology, biomedical, and food industries remain primary our target audiences for this research. Probiotics, food fermentation, and minimizing food pathogens is a primary effort of these industries to maintain a safe food supply and to enhance human health. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training to postdoctoral scientists (Dr. Wenting Ju, Dr. Zhangyuan Zhai, Dr. Mary Moore, Dr. Sandra Appelt, Dr. Kanika Chauhan), graduate students (Benjamin Golomb, Zachary Bendiks, Dustin Heeney, and Zhengyao Xue, Xiaochen Yin), technicians (Jose Zaragoza, Brendan McCarthy-Sinclair, and Jason Brooks), and undergraduate student interns. Training to Ben Golomb and Xiaochen Yin were also provided during an industry internship. The individuals on the project received training from Dr. Marco on lactic acid bacteria and gut microbiology, HTP DNA sequencing microbial diversity analysis, and mechanisms of intestinal inflammation. These individuals are responsible for conducting animal and bacteriology experiments well as analyzing results in cooperation with Dr. Marco. How have the results been disseminated to communities of interest?Dissemination events include conference presentations, published journal articles, and consultations with local and international food processors and members of the media. Dissemination of knowledge beyond a scientific audience has included on-site tours of the research laboratory and description of the research program to university students, international visitors, casual visitors to the university (members of the public) and stakeholders (representing industrial sectors related to food science, nutrition, and health). What do you plan to do during the next reporting period to accomplish the goals?Activities for the next reporting period encompass the further development of all three objectives to achieve the goals of the project. For objective 1, we will continue investigations on the food microbiomes as they pertain to the function of model LAB in those food environments. We will also continue our on-going investigations on the mechanisms by which selected strains of LAB provide benefits to olive fermentations. Model strains (e.g. Lplantarum NCIBM8826 (WCFS1)) will be used for this research. Lastly, efforts will be made to deepen our analysis of host-diet effects on the intestinal microbiome, with particular regard to intestinal Lactobacillus. Dissemination of the results will be through published articles in peer-reviewed journals, a PhD thesis, direct meetings with industrial stakeholders, and communications to the press and the public.

Impacts
What was accomplished under these goals? Accomplishments during this period encompass publications and outreach efforts aimed at disseminating knowledge on lactic acid bacteria (LAB). For objective 1, we published our findings on the identification of a non-ribosomal polyketide synthesis system in Lactococcus lactis (Microbiology Open). This work showed how this unique system is important to L. lactis survival during exposure to oxidative stress. For Objective 2, we published a paper on the population dynamics of bacteria and fungi in olive fermentations when exposed to starter culture bacteria and spoilage yeast (mSphere). For objective 3, our report on the influence of host diet on probiotic L. plantarum interactions with the intestinal microbiota was released (Scientific Reports). Xiaochen Yin's PhD thesis also resulted from these efforts. Results from this work and my other ongoing research pertaining to (model) lactic acid bacteria and their interactions with food and gut microbiomes were presented at numerous international conferences at various sites around the country and attended by industry, academics and the lay-public.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Jose Zaragoza, Zachary Bendiks, Charlotte Tyler, Mary E. Moore, Tom Williams, Yelizaveta Luchkovska, Elaine Chow, Kyria Boundy Mills, and Maria L Marco. 2017. Effects of exogenous yeast and bacteria on microbial population dynamics and outcomes of olive fermentations. mSphere 2:e00315-16. https://www.ncbi.nlm.nih.gov/pubmed/28124026
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Benjamin L. Golomb, Annabelle O. Yu, Laurynne C. Coates, and Maria L. Marco. 2017. The Lactococcus lactis KF147 non-ribosomal peptide synthetase/polyketide synthase system confers resistance to oxidative stress during growth on plant leaf tissue lysate. Microbiology Open 10.1002/mbo3.519. https://www.ncbi.nlm.nih.gov/pubmed/28921941
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Xiaochen Yin and Maria L. Marco. 2017. Host diet changes the population dynamics of indigenous and dietary Lactobacillus in the digestive tract. Scientific Reports 7: 7267 https://www.nature.com/articles/s41598-017-07428-w
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Intestinal Lactobacillus measured by -omics approaches. International Scientific Association for Probiotics and Prebiotics, Chicago, IL 6/28/2017
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: L. plantarum as model to study ingested microbe - host interactions. UC Davis Host-Microbiome Interactions Retreat. 10/28/216
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Environmental Factors Affecting the Ecological Fitness of Lactobacillus in Mammalian Digestive Tracts


Progress 10/01/15 to 09/30/16

Outputs
Target Audience:The food system is worldwide. However, the US and California agricultural, biotechnology, biomedical and food industries remain primary our target audiences for this research. Probiotics, food fermentation, and minimizing food pathogens is a primary effort of these industries to maintain a safe food supply and to enhance human health. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training to postdoctoral scientists (Dr. Wenting Ju, Dr. Zhangyuan Zhai, Dr. Mary Moore, Dr. Sandra Appelt, Dr. Kanika Chauhan), graduate students (Benjamin Golomb, Zachary Bendiks, Dustin Heeney, and Zhengyao Xue), technicians (Jose Zaragoza and Brendan McCarthy-Sinclair), and undergraduate student interns. Training to Ben Golomb was also provided during an industry internship. Ben and the other individuals on the project received training from Dr. Marco on lactic acid bacteria and gut microbiology, HTP DNA sequencing microbial diversity analysis, and mechanisms of intestinal inflammatoy. These individuals are responsible for conducting animal and bacteriology experiments well as analyzing results in cooperation with Dr. Marco. How have the results been disseminated to communities of interest?Dissemination events include conference presentations, published journal articles, and consultations with local and international food processors and members of the media. Dissemination of knowledge beyond a scientific audience has included on-site tours of the research laboratory and description of the research program to university students, international visitors, casual visitors to the university (members of the public) and stakeholders (representing industrial sectors related to food science, nutrition, and health). What do you plan to do during the next reporting period to accomplish the goals?Activities for the next reporting period encompass the further development of all three objectives to acheive the goals of the project. For objective 1, we will continue investigations on the plant- and milk-associated microbiomes as they pertain to the function of LAB in those food environments. We will also continue our on-going investigations on the mechanisms by which selected strains of LAB provide benefits to olive fermentations. Model strains (e.g. Lplantarum NCIBM8826 (WCFS1) will be used for this research. Lastly, efforts will be made to deepen our analysis of host-diet effects on the intestinal microbiome, with particular regard to intestinal Lactobacillus. Dissemination of the results will be through published articles in peer-reviewed journals, a PhD thesis, direct meetings with industrial stakeholders, and communications to the press and the public.

Impacts
What was accomplished under these goals? Accomplishments during this period encompass publications and outreach efforts aimed at disseminating knowledge on lactic acid bacteria (LAB). For objective 1, we characterized the microbial composition of milk and cheese, primary habitats for a variety of LAB. LAB are essential for cheese fermentations but growth of certain strains/species can also cause spoilage defects. Outcomes of our research were published in mBio in 2016. To support the deeper analysis of bacterial species, strains, and pathovars in food environments, we published two molecular detection papers (Frontiers Microbiol and J Am Chem Society in 2016). Complementary to these efforts was a PhD thesis published on LAB adaptations to their native habitats (Golomb UC Davis 2016). For Objective 2, we initiated experiments to characterized model L. plantarum strain adaptations to olive fermentations. These studies are still ongoing in 2017. For objective 3, we published a paper on the (meta)transcriptome of the small intestine containing L plantarum (Sci Reports). Results from this work and my other ongoing research pertaining to the effects of host diet on the gut microbiome and probiotic function were presented at numerous international conferences at various sites around the country and attended by industry, academics and the lay-public.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Benjamin L. Golomb, Lauren A. Hirao, Satya Dandekar, and Maria L. Marco. 2016. Gene expression of�Lactobacillus plantarum�and the commensal microbiota in the ileum of healthy and early SIV-infected rhesus macaques. Scientific Reports 6:24723
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Wenting Ju, Anne-Laure Moyne, Maria L Marco. 2016. RNA-based detection does not accurately enumerate living Escherichia coli O157:H7 cells on plants. Frontiers in Microbiology. 7:233.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Pallavi Daggumati, Sandra Appelt, Zimple Matharu, Maria L. Marco, Erkin Seker. 2016. Sequence-specific electrical purification of nucleic acids with nanoporous gold electrodes. Journal of the American Chemical Society. 138(24):7711 -7717.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Mary E. Moore, Yanin Srisengfa, Miles Laird, Jose Zaragoza, Jeremy McLeod, Jessie Heidenreich, and Maria L. Marco. 2016. The core and seasonal microbiota of raw bovine milk in tanker trucks and the impact of transfer to a milk processing facility. mBio. 2016 Jul-Aug; 7(4): e00836-16.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Invited Speaker. Forces shaping Lactobacillus populations in the intestine, Wageningen University, The Netherlands
  • Type: Theses/Dissertations Status: Published Year Published: 2016 Citation: Adaptations of lactic acid bacteria to their hosts and ecological niches
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Invited talk: Probiotics: Fact and Fiction, The Natural Ingredients Expo, Anaheim, CA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Probiotics: Fact and Fiction. Natural Products Expo, Anaheim, CA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: State of probiotics research, Ingredients Marketplace, Orlando, FL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Targeting the microbiome to improve the health of obese individuals, UC Davis Department of Internal Medicine Liver Day Research Symposium
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Recent advances in probiotics and microbiome research, Supply Side West, San Diego, CA


Progress 01/26/15 to 09/30/15

Outputs
Target Audience:The food system is worldwide. However, the US and California agricultural, biotechnology, biomedical and food industries remain primary our target audiences for this research. Probiotics, food fermentation, and minimizing food pathogens is a primary effort of these industries to maintain a safe food supply and to enhance human health. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training to postdoctoral scientists (Dr. Zhangyuan Zhai, Dr. Mary Moore, and Dr. Sandra Appelt), graduate students (Benjamin Golomb, Zachary Bendiks, Dustin Heeney, Zhengyao Xue), technician (Jose Zaragoza), and undergraduate student interns. Training to Ben Golomb was also provided during an industry internship. Ben and the other individuals on the project received training from Dr. Marco on lactic acid bacteria and gut microbiology, HTP DNA sequencing microbial diversity analysis, and mechanisms of IBD. These individuals are responsible for conducting animal and bacteriology experiments well as analyzing results in cooperation with Dr. Marco. How have the results been disseminated to communities of interest?Dissemination events include conference presentations, published journal articles, and consultations with local and international food processors and members of the media. Dissemination of knowledge beyond a scientific audience has included on-site tours of the research laboratory and description of the research program to university students, international visitors, casual visitors to the university (members of the public) and stakeholders (representing industrial sectors related to food science, nutrition, and health). What do you plan to do during the next reporting period to accomplish the goals?Activities for the next reporting period include further development of objective 1 of the project. This work encompasses the advancement of the findings of L. casei BL23 in milk and L. lactis KF147 on plant materials. For objective 2 of the project, we will investigate the mechanisms by which select strains of LAB provide benefits to olive fermentations. Also planned for the reporting period is advancement on objective 3 and on-going studies to elucidate effects of diet on the intestinal microbiome and specifically Lactobacillus in the human intestine. Dissemination of the results will be through published articles in peer-reviewed journals, a PhD thesis, direct meetings with industrial stakeholders, and communications to the press and the public.

Impacts
What was accomplished under these goals? Accomplishments during this period encompass experiments investigating how food-associated lactic acid bacteria (LAB) adapt to their food matrices for growth and survival (objective 1). These experiments also encompass how those adaptations are important to the functionality of those bacteria in the digestive tract. Firstly, we identify proteins produced by dairy-associated, probiotic, LAB Lactobacillus casei BL23 in milk. Using shot-gun proteomics approaches we identified proteins made by this organism specifically during low temperature incubation in milk. We also confirmed the importance of some of those proteins in milk and for L. casei after it is consumed during transit through the mammalian GI tract. Complementary to this work was our elucidation of genes expressed by the LAB Lactococcus lactis KF147 during growth on plant leaf tissues. We investigated its metabolic outputs during growth on plants as well as identified novel properties expressed by this strain specifically in plant environments. The studies on L. casei and L. lactis provide novel insight into how LAB adapt for growth in their native environments (e.g. milk and plants) in ways important for their roles as probiotics (L. casei) and starter cultures in food fermentations (L. lactis).We have had publications and presentations on these topics this past year. Other accomplishments in this project period encompass objective 3. Specifically, we have investigated how diet affects the indigenous intestinal microbiota and, specifically Lactobacillus. This work is employing modern DNA and RNA sequencing methods to examine how the addition of fiber into a Western diet can stimulate the growth of probiotic bacteria in the intestine to reduce the risk for metabolic diseases such as Type 2 diabetes mellitus. This work is also integrated with the detection of those bacteria using next-generation sensor technology. We have had publications and presentations on on this topic during the past year.

Publications

  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Jing C. Zhou, Bob Feller, Bill Hinsberg, Geeta Sethi, Paul Feldstein, Joshua Hihath, Erkin Seker, Maria L. Marco, Andre Knoesen, and Robert Miller. 2015. Immobilization-mediated reduction in melting temperatures of DNA-DNA and DNA-RNA hybrids: solid state DNA probe hybridization studied by SPR. Colloids and Surfaces A: Physicochemical and Engineering Aspects 481:72 -79. http://www.sciencedirect.com/science/article/pii/S0927775715003866
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Bokyung Lee, Sybille Tachon, Richard A Eigenheer, Brett S Phinney, and Maria L Marco. 2015. Lactobacillus casei low-temperature, dairy-associated proteome promotes persistence in the mammalian digestive tract. Journal of Proteome Research. 14(8):3136-47 http://pubs.acs.org/doi/abs/10.1021/acs.jproteome.5b00387
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Bokyung Lee, Xiaochen Yin, Stephen M. Griffey, and Maria L. Marco. 2015. Attenuation of colitis by Lactobacillus casei BL23 is dependent on the dairy delivery matrix. Applied Environmental Microbiology 81(18):6425-35. http://aem.asm.org/content/early/2015/07/07/AEM.01360-15
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Invited speaker at the American Society for Microbiology meeting, New Orleans, Louisiana.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Invited speaker at the 33rd International Symposium on Diabetes and Nutrition, Toronto, Ontario, Canada.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Invited speaker. Global Cheese Technology Forum, Reno, Nevada