Ashish Tyagi

Role of surface layer collagen binding protein from indigenous Lactobacillus plantarum 91 in adhesion and its anti-adhesion potential against gut pathogen

Human feacal isolates were ascertain as genus Lactobacillus using specific primer LbLMA1/R16-1 and further identified as Lactobacillus plantarum with species specific primers Lpl-3/Lpl-2. 25 L. plantarum strains were further assessed for hydrophobicity following the microbial adhesion to hydrocarbons (MATH) method and colonization potentials based on their adherence to immobilized human collagen type-1. Surface proteins were isolated from selected L. plantarum 91(Lp91) strain. The purified collagen binding protein (Cbp) protein was assessed for its anti-adhesion activity against enteric Escherichia coli 0157:H7 pathogen on immobilized collagen. Four L. plantarum strains displayed high degree of hydrophobicity and significant adhesion to collagen. A 72 kDa protein was purified which reduced 59.71% adhesion of E. coli 0157:H7 on immobilized collagen as compared to control well during adhesion assay. Cbp protein is the major influencing factor in inhibition of E. coli 0157:H7 adhesion with extracellular matrix (ECM) components. Hydrophobicity and adhesion potential are closely linked attributes precipitating in better colonization potential of the lactobacillus strains. Cbp is substantiated as a crucial surface protein contributing in adhesion of lactobacillus strains. The study can very well be the platform for commercialization of indigenous probiotic strain once their functional attributes are clinically explored.

Polyunsaturated fatty acids in male ruminant reproduction: A review.

Fatty acids such as n-3 and n-6 polyunsaturated fatty acids (PUFA) are critical nutrients, used to improve male reproductive performance through modification of fatty acid profile and maintenance of sperm membrane integrity, especially under cold shock or cryopreservation condition. Also, PUFA provide the precursors for prostaglandin synthesis and can modulate the expression patterns of many key enzymes involved in both prostaglandin and steroid metabolism. Many studies carried out on diets supplemented with PUFA have demonstrated their capability to sustain sperm motility, viability and fertility during chilling and freezing as well as improving testis development and spermatogenesis in a variety of livestock species. In addition to the type and quantity of dietary fatty acids, ways of addition of PUFA to diet or semen extender is very crucial as it has different effects on semen quality in male ruminants. Limitation of PUFA added to ruminant ration is due to biohydrogenation by rumen microorganisms, which causes conversion of unsaturated fatty acids to saturated fatty acids, leading to loss of PUFA quantity. Thus, many strategies for protecting PUFA from biohydrogenation in rumen have been developed over the years. This paper reviews four aspects of PUFA in light of previous research including rumen metabolism, biological roles, influence on reproduction, and strategies to use in male ruminants.

Synthetic Biology: Applications in the Food Sector

Synthetic biology also termed as “genomic alchemy” represents a powerful area of science that is based on the convergence of biological sciences with systems engineering. It has been fittingly described as “moving from reading the genetic code to writing it” as it focuses on building, modeling, designing and fabricating novel biological systems using customized gene components that result in artificially created genetic circuitry. The scientifically compelling idea of the technological manipulation of life has been advocated since long time. Realization of this idea has gained momentum with development of high speed automation and the falling cost of gene sequencing and synthesis following the completion of the human genome project. Synthetic biology will certainly be instrumental in shaping the development of varying areas ranging from biomedicine, biopharmaceuticals, chemical production, food and dairy quality monitoring, packaging, and storage of food and dairy products, bioremediation and bioenergy production, etc. However, potential dangers of using synthetic life forms have to be acknowledged and adoption of policies by the scientific community to ensure safe practice while making important advancements in the ever expanding field of synthetic biology is to be fully supported and implemented.

Adhesion of Lactobacilli and their anti-infectivity potential

ABSTRACT The probiotic potential of lactic acid bacteria primarily point toward colonizing ability of Lactobacilli as the most important attribute for endowing all the known beneficial effects in a host. Lactobacillus species exert health-promoting function in the gastrointestinal tract through various mechanisms such as pathogen exclusion, maintenance of microbial balance, immunomodulation, and other crucial functions. It has been seen that many surface layer proteins are involved in host adhesion, and play significant role in the modification of some signaling pathways within the host cells. Interaction between different bacterial cell surface proteins and host receptor has been imperative for a better understanding of the mechanism through which Lactobacilli exert their health-promoting functions.

Assessing safety of Lactobacillus plantarum MTCC 5690 and Lactobacillus fermentum MTCC 5689 using in vitro approaches and an in vivo murine model

ABSTRACT Lactobacilli have a long history of safe use in human nutrition, however, inclusion of any new strain, despite its safe usage evidence, warrants proper analysis of its safety and toxicity under the purview of existing regulations. In the present investigation, Lactobacillus plantarum MTCC 5690 and Lactobacillus fermentum MTCC 5689 were evaluated for their safety and toxicity using both in vitro and in vivo approaches. The in vitro assays included mucin degradation, hemolytic activity, biogenic amine production and platelet aggregation assay. The safety was also assessed using acute, subacute and subchronic assays, bacterial translocation studies, intravenous and intravenous administration and genotoxicity assay in murine model. The outcome of this toxicological safety assessment indicated that both the test strains lacked any harmful metabolic activity or any genotoxic effects. Furthermore, the results of oral toxicity studies in mice revealed that short term administration of high cell mass concentration of 1012 cfu/animal as well as long term feeding of the probiotic strains did not alter any hematological, general health parameters or cause any organ specific disorder. Based upon these scientific assessments and supported by long history of safe use, both MTCC 5690 and MTCC 5689 may be considered safe for human consumption. Graphical abstract Figure. No caption available. HighlightsTwo putative probiotic Lactobacilli strains evaluated for their safety using in vitro approaches and in vivo murine model.Test strains exhibited negative mucin degradation, hemolytic, biogenic amine formation and platelet aggregation activity.No toxicity related disorders were reported in mice during acute, sub‐acute and sub‐chronic oral toxicity tests.Test strains found safe during intravenous and intravenous administration in mice and also devoid of any genotoxic effects.

Influence of Levels of Metabolisable Protein in the Ration on Nutrient Utilization and Lactation Performance in Murrah Buffaloes

The present study was conducted to ascertain the effects of feeding varying levels of metabolisable protein on the nutrient utilization and production performance in Murrah buffaloes. Sixteen Murrah buffaloes in advanced stage of pregnancy (40–50 d before parturition) were divided into 3 groups on the basis of most probable production ability (MPPA) and lactation number. Duration of feeding trial was 130 days (40 days pre-partum to 90 days post-partum period. The animals were fed 3 different diets as low metabolizable protein (LMP), medium metabolizable protein (MMP) and high metabolizable protein (HMP) at MP levels of 85, 100 and 115% of ICAR (2013) recommendations, respectively, however, the diets had similar metabolisable energy (ME) content. The intakes of DM, ME and TDN were similar in all the experimental groups. The CP and MP intakes before and after calving were higher (P<0.05) in HMP followed by MMP and LMP groups. The digestibility of DM, OM, EE, NDF and ADF was similar in 3 groups whereas the digestibility of CP was higher (P<0.05) in HMP compared to LMP groups. Milk yield efficiency (kg/kg DMI), 6% FCM and FCM production efficiency were lower on feeding low MP diet. There was no significant change in the concentrations of β-HBA, glucose and IGF-1 on varying MP intake. Hence, feeding 75% lower MP than ICAR, 2013 recommendation in the ration decreased milk production and CP digestibility.

Significance of Probiotics as Feed Additives in Livestock and Poultry Nutrition

A number of feed additives such as antibiotics, probiotics, oligosaccharides, enzymes and organic acids have been used in livestock feeds for improving productivity and maintaining gut eubiosis. Antibiotics have been widely used in livestock diets, however, development of antimicrobial resistance to these antibiotics urged scientists to find viable alternatives to the use of antibiotics that could enhance the productivity as well as natural defense mechanisms of animals. Probiotics are technically viable alternatives to antibiotics in livestock feed. Probiotics are the live culture of host-friendly microbes which upon ingestion exert health effects to the host. Probiotics have been established as a good alternative which can enhance intestinal health by stimulating the development of a healthy microbiota (predominated by beneficial bacteria), competing with pathogenic bacteria for nutrients in the gut, preventing enteric pathogens from colonizing the intestine, increasing digestive capacity and lowering the pH and altering mucosal immunity. Moreover, nutritional intervention through probiotics supplementation seems be a natural and holistic strategy to combat such challenges. The beneficial response to probiotics supplementation seems to be affected by both source and dose of probiotics supplemented in particular species. The present review is an attempt to explore the use of different probiotics in livestock feed and thetr probable mode of actions through which they exhibit their beneficial effects in animals.

In Vitro Evaluation of Different Concentrations of Linoleic Acid on Hydrogenation Pattern of Fatty Acids by In-1 Strain of Butyrivibrio fibrisolvens

In the present study, the effect of sunflower oil as a source of linoleic acid (LA) on production of conjugated linoleic acid (CLA) by anaerobic Butyrivibrio fibrisolvens In-1 bacteria was evaluated. Initially, B. fibrisolvens In-1 was inoculated in anaerobic ATCC media having same amount (250 μg/ml of media) of four different dietary oils and incubated for 24 h. Supplementation of sunflower oil resulted in the highest CLA production by B. fibrisolvens In-1 among the treatments which was further used for in vitro study. Different concentrations of linoleic acid (0, 100, 200, 300, 400 and 500 μg/ml of media) were used and incubated for different time intervals (0, 2, 4, 6, 8, 10, 24, 36 and 48 h) in ATCC anaerobic media. The highest CLA production (103.32 μg/ml) was recorded with 400 μg/ml linoleic acid at 8 h of incubation period and the maximum growth occurred when incubation was done with 100 μg/ml free linoleic acid for 6 h and decreased further with time and increased linoleic acid concentration. The results indicated that higher concentration of linoleic acid had negative effect on the growth and CLA production potential of Butyrivibrio fibrisolvens In-1.