Isolation and characterization of reductive acetogens from rumen fluid samples of Murrah buffaloes.

In the present study, attempts have been made to isolate reductive acetogens from the rumen fluid samples of Murrah buffaloes (Bubalus bubalis). Out of 32 rumen samples 51 isolates were isolated, and based on autotrophic growth for production of acetate and presence of formyltetrahydrofolate synthetase gene (FTHFS) 12 isolates were confirmed as reductive acetogens. Microscopic observations showed that ten isolates as Gram-positive rods (ACB28, ACB29, ACB66, ACB73, ACB81, ACB91, ACB133, ACB229, ACB52, ACB95) and two isolates as Gram-positive cocci (ACB19, ACB89). All isolates tested negative for catalase, oxidase, and gelatin liquefaction, whereas the production of H2S was detected for two (ACB52 and ACB95) of the above isolates. All these isolates showed autotrophic growth from H2 and CO2, and heterotrophic growth with different fermentable sugars, viz., d-glucose, D-fructose, and D-trehalose but failed to grow on salicin, raffinose, and l-rhamnose. Out of the isolates, two showed amylase activity (ACB28 and ACB95), five showed CMCase activity (ACB19, ACB28, ACB29, ACB73 and ACB91), three showed pectinase activity (ACB29, ACB52 and ACB89), whereas none of the isolates was found positive for avicellase and xylanase activity. Based on 16S rDNA gene sequence analysis, the isolates showed their phylogenetic relationship with maximum similarity up to 99% to different strains of earlier reported known acetogens of clostridia group including Clostridium sp. (6), Eubacterium limosum (1), Ruminococcus sp. (1) and Acetobacterium woodii (1) except one, i.e., Vagococcus fluvialis. The results indicate that reductive acetogens isolated from the rumen fluid samples of Murrah buffalos are both autotrophic and heterotrophic in nature and further investigations are required to exploit and explore their potential as an alternate hydrogen sink.

Different Treatments for Sugarcane Juice Preservation.

This investigation aimed to optimize the time, pH, pressure, and temperature of sugarcane juice pasteurization and to develop a "ready to serve" bottled sugarcane juice with a high preservation efficiency. Fresh sugarcane juice was extracted from sugarcane genotype Co 89003, and beverage samples were collected using three different treatments: sulphitation of juice with the addition of potassium metabisulphite (KMS-25, 50, 100, and 150 ppm), acidification of juice (addition of citric acid, to reduce the pH of the juice to 4.8, 4.5, and 4.25), and steam treatment of the canes (5 min, 10, and 15 min at 7 psi). In all treatments, the juice was pasteurized in glass bottles @ 65 °C for 25 min and stored at low temperature (5 °C) in pre-sterilized glass bottles. Juice properties such as the ˚Brix, total sugar, pH, and total phenolic content decreased with storage, whereas the microbial count, titrable acidity, and reducing sugar content significantly increased during storage. The addition of KMS, citric acid, and the steam treatment reduced the browning of juice and maintained the color of juice during storage, by inhibiting the polyphenol oxidase enzyme activity, from 0.571 unit/mL to 0.1 unit/mL. Among the selected treatments, sugarcane juice with KMS (100 and 150 ppm) and steam treatment of the canes for 5 and 10 min at 7 psi showed the minimum changes in physico-chemical properties, sensory qualities, and restricted microbial growth. Thesulphitation treatment with pasteurization proved best for increasing the shelf life of sugarcane juice upto 90 days with refrigeration. Similarly, the steam-subjected cane juice (10 and 15 min at 7 psi) could be effectively preserved for upto 30 days with refrigeration, without any preservative.

Efficacy of BOX-PCR fingerprinting for taxonomic discrimination of bifidobacterial species isolated from diverse sources.

The genus Bifidobacterium are extensively used as probiotics in food applications, for their potential role to combat different lifestyle diseases. This has necessitated a great importance for their species, sub-species and even at the strain level characterization. In the present study, attempts have been made to target repetitive DNA element-based BOX-PCR fingerprinting to judge its potential in taxonomic discrimination of Bifidobacterium species. The BOXA1R primer-based repetitive PCR amplified products were analysed for 93 identified bifidobacterial isolates collected from diverse sources of human and animal origin along with 12 DSMZ procured standard reference strains. Dendrograms constructed from the fingerprint patterns of BOX-PCR differentiated all the isolated strains into 10 different groups, grouped with one standard reference isolates and successfully discriminated all isolates up to subspecies level as identified. The BOX-PCR method used in this study effectively resolved the taxonomic status and differentiated all 93 bifidobacterial species isolated from diverse faecal origins of human and animal samples.

Bioavailability assessment of zinc enriched lactobacillus biomass in a human colon carcinoma cell line (Caco-2).

The present study utilizes lactobacilli strains having the potential to accumulate a significant amount of Zinc (Zn) in their biomass and ability to deliver the same mineral in a highly bioavailable form. A human origin Lactobacillus fermentum SR4 and Lactobacillus rhamnosus GG (LGG) were studied for their ability to accumulate Zn by growing them in the medium containing Zn salt. Further, Zn enriched cell lysates were prepared by Ultrasonication, as an organic Zn source. Various functional groups involved in bacterial Zn binding were identified by FT-IR spectroscopy and elemental Zn in bio-chelated cell lysate complex was confirmed by SEM and Energy Dispersive X-ray Spectrometry (EDX). Experimental data demonstrated a significantly higher (P < 0.05) bioavailability of Zn chelated by SR4 followed by LGG i.e., 57% and 48%, as compared to the commercially available inorganic (ZnSo4) and even organic (Zinc gluconate) forms tested which has 15.6% and 21.7% respectively.

Alteration in physicochemical, functional, rheological and reconstitution properties of milk protein concentrate powder by pH, homogenization and diafiltration.

Concentration of milk proteins by ultrafiltration (UF) and diafiltration (DF) processes during manufacturing of milk protein concentrate (MPC) powders alter their natural milk protein stabilization system. Increasing calcium and protein contents often leads to poor functional properties in MPC powders. The pH adjustment using disodium phosphate (DSP, Na2HPO4) and DF with 150 mM NaCl solution of UF retentate were hypothesized to produce desirable changes in various properties of resulted MPC powders. Addition of Na2HPO4 followed by homogenization; DF of 5 × UF retentate with 150 mM NaCl solution resulted in significant improvement in the dispersibility, wettability, flowability, solubility, heat stability, buffer index, emulsification and foaming and water and oil binding capacities of the MPC powders. The solubility of developed MPC powders was significantly higher than MPC-C powder in fresh as well as even after 90 days of storage at 25 ± 1 °C. Rheological behaviour of reconstituted MPC was best explained by Herschel Bulkley model. Scanning electron microscopy micrograph indicated that MPC powders were having smooth surfaced, intact and separate smaller particles compared to rough, larger, infused aggregates with dents in MPC-C. Technological interventions applied are easier to adopt, cost-effective and efficient in producing excellent quality MPC powders that may find applications in wide range of novel food formulations.

Bovicins: The Bacteriocins of Streptococci and Their Potential in Methane Mitigation.

Bovicin is a type AII lantibiotic, possessing two ß-methyllanthionine and a disulfide bridge encoded by bovA gene hitherto unknown a couple of decades ago. Bacteriocins can be useful in directly inhibiting methanogens and/or redirecting H2 to other reductive microorganisms, in particular, propionate producers or reductive acetogens. So far, the role of nisin and bovicin to suppress greenhouse gas (GHG) production under in vitro conditions has been documented. GHG emissions from ruminants are a threat to the environment, because of their role in global warming as well as in climate change. Methane (CH4) produced from livestock farming practices is a potent GHG, comprising 18% of total GHG emissions in the world. Therefore, minimizing enteric CH4 production is quite essential from both the economical livestock production as well as environment perspectives. Strategies for the abatement of CH4 have provided two-way opportunities, viz., improved livestock productivity and reduced GHG emissions. In the past, different strategies have been proposed and tested to mitigate CH4, such as the dietary composition of feeds, ionophores, antibiotics, vaccines, analogues, probiotics, and secondary metabolites of plants and fungi. However, quite a few of these strategies have been adopted at farm level due to their varied effect on animal health and/or residues on animal products. The use of bacteriocins might have potential in inhibiting methanogens in the rumen. A bacteriocin produced by Streptococcus bovis (an isolate from rumen) named bovicin HC5 has been exhibited to decrease CH4 production to an extent of 50%. In this review, authors intend to discuss the sources, structure, biochemical properties, and antimicrobial spectra of bovicins, besides the potential applications with special reference to CH4 mitigation.

Effect of Lactobacillus rhamnosus NCDC 298 with FOS in Combination on Viability and Toxin Production of Enterotoxigenic Escherichia coli.

The present study was to investigate the utilization of prebiotics by Lactobacillus rhamnosus NCDC 298 and its synergistic adversary effect on both population and production of heat-labile (LT) toxin in enterotoxigenic Escherichia coli (ETEC). To select suitable prebiotic in order to enhance functionality, its utilization and the prebiotic activity score was examined. Antivirulence effect on ETEC was inspected by its inactivation rate and heat-labile toxin production in presence of different synbiotic combination. L. rhamnosus NCDC 298 strain grown well on media supplemented with fructooligosaccharides (FOS) and galactooligosaccharides (GOS), whereas significant inactivation of ETEC was observed when FOS was added to the co-culture medium. Significant decrease in LT enterotoxin was seen through GM1 ganglioside enzyme linked immunoassay (GM1 ELISA), when ETEC has grown with L. rhamnosus NCDC 298 and FOS. Short-chain FOS proved to be the most effective substrate, improving antagonistic activity for L. rhamnosus NCDC 298. Both L. rhamnosus NCDC 298 with FOS can be used as an effective synbiotic combination for secretory antidiarrheal fermented dairy formulations.

Antibiotic susceptibility profile of Pediococcus spp. from diverse sources.

The aim of the present study was to assess the antibiotic susceptibility profile of Pediococcus strains from diverse sources. From a total of 115 dairy and non-dairy samples, 40 Pediococcus strains were isolated. Their biochemical and molecular characterization confirmed them as P. pentosaceus and P. acidilactici. All the 40 identified isolates were evaluated for antibiotic susceptibility using disc diffusion assay against a total of 20 antibiotics. The isolates exhibited varied range of responses towards the antibiotics depending on the strain type, source and location of isolation. All the isolates were either sensitive or intermediate resistant to amoxycillin, erythromycin, ceftriaxone, cloxacillin, cefoperazone, penicillin, netillin, gentamycin and chloramphenicol. Resistance towards vancomycin and nalidixic acid was exhibited by most of the isolates. A total of 16 strains belonging to dosa batter (n = 4; n = number of isolates), fermented vegetables (n = 4), fermented grape juice (n = 4), idly batter (n = 3) and the only isolate from butter milk exhibited sensitivity/intermediate towards 80-90% of the studied antibiotics. No considerable difference in susceptibility pattern was observed between the two Pediococcus species, i.e., P. pentosaceus and P. acidilactici. Overall, the maximum resistance was exhibited by isolates belonging to silage (Sil-2; 50%) followed by cow milk (PD-41), dosa batter (8-PD) and human isolate (PD-45) which showed resistance towards 40% of studied antibiotics. The susceptibility profiling of Pediococcus strains will be helpful in their safer selection for future food and feed applications.

Effect of pH adjustment, homogenization and diafiltration on physicochemical, reconstitution, functional and rheological properties of medium protein milk protein concentrates (MPC70).

Poor solubility is the major limiting factor in commercial applications of milk protein concentrates (MPC) powders. Retentate treatments such as pH adjustment using disodium phosphate (Na2HPO4), also responsible for calcium chelation with homogenization and; its diafiltration with 150 mM NaCl solution were hypothesized to improve the functional properties of treated MPC70 powders. These treatments significantly improved the solubility, heat stability, water binding, dispersibility, bulk density, flowability, buffer index, foaming and emulsifying capacity of treated powders over control. Rheological behaviour of reconstituted MPC solutions was best explained by Herschel Bulkley model. Compared to rough, large globular structures with dents in control; majorly intact, separate, smaller particles of smooth surface, without any aggregation were observed in SEM micrograph of treated powders. Applied treatments are easy, cost-effective and capable to improve functional properties of treated powders that could replace control MPC70 powder in various food applications where protein functionality is of prime importance.

Bio-prospectus of cadmium bioadsorption by lactic acid bacteria to mitigate health and environmental impacts.

Foodstuffs and water are the key sources of cadmium biomagnifiaction. The available strategies to mitigate this problem are unproductive and expensive for practical large-scale use. Biological decontamination of metals through environmental microbes has been known since long time, whereas lactic acid bacteria (LAB) have not been extensively studied for this purpose. The LAB are known for maintaining homeostasis and suppression of pathogens in humans and animals. They also play a vital role in bioremediation of certain heavy metals. Recently in-vivo research findings strongly complement the in-vitro results in relation to decreased total body cadmium burden in animal model. This review summarizes the currently available information on impact of toxic metal (Cd) on human and animal health as well as cadmium sequestration through microbes placed broadly, whereas preeminent attention grabbed on LAB-cadmium interaction to explore their possible role in bioremediation of cadmium from foods and environment to safeguard human as well as environment health.

BIOAVAILABILITY OF BIOTRANSFORMED ZINC ENRICHED DAHI IN WISTAR RATS.

In the present study, we have investigated the bioavailability of biotransformed organic zinc enriched dahi in vivo. The results evidence that the rats fed with zinc enriched dahi (ZED and ZEP) significantly increased (p<0.001) body weight and food intake from zero to third weeks. Analysis of zinc by AAS in body parts of different rat groups indicated that zinc content was significantly higher (p<0.001) in serum, femur bone, liver and hair of rats fed ZED/ZEP. Basal diet and inorganic zinc sulphate fed rat group excreted a greater amount of zinc in faeces. The results of in-vivo studies indicated that the bioavailability of organic zinc through dahi/probiotic dahi is high compared to its inorganic form.

Riboflavin and health: A review of recent human research.

There has lately been a renewed interest in Riboflavin owing to insight into its recognition as an essential component of cellular biochemistry. The knowledge of the mechanisms and regulation of intestinal absorption of riboflavin and its health implications has significantly been expanded in recent years. The purpose of this review is to provide an overview of the importance of riboflavin, its absorption and metabolism in health and diseased conditions, its deficiency and its association with various health diseases, and metabolic disorders. Efforts have been made to review the available information in literature on the relationship between riboflavin and various clinical abnormalities. The role of riboflavin has also been dealt in the prevention of a wide array of health diseases like migraine, anemia, cancer, hyperglycemia, hypertension, diabetes mellitus, and oxidative stress directly or indirectly. The riboflavin deficiency has profound effect on iron absorption, metabolism of tryptophan, mitochondrial dysfunction, gastrointestinal tract, brain dysfunction, and metabolism of other vitamins as well as is associated with skin disorders. Toxicological and photosensitizing properties of riboflavin make it suitable for biological use, such as virus inactivation, excellent photosensitizer, and promising adjuvant in chemo radiotherapy in cancer treatment. A number of recent studies have indicated and highlighted the cellular processes and biological effects associated with riboflavin supplementation in metabolic diseases. Overall, a deeper understanding of these emerging roles of riboflavin intake is essential to design better therapies for future.

Screening of Riboflavin-Producing Lactobacilli by a Polymerase-Chain-Reaction-Based Approach and Microbiological Assay.

Riboflavin has an important role in various cellular metabolic activities through its participation in oxidation-reduction reactions. In this study, as many as 60 lactobacilli were screened for the presence or absence of riboflavin biosynthesis genes and riboflavin production. Of these, only 14 strains were able to grow in a commercial riboflavin-free medium. We observed that the presence of riboflavin biosynthesis genes is strain-specific across different species of lactobacilli. The microbiological assay was found to be appreciably reproducible, sensitive, rapid, and inexpensive and, hence, can be employed for screening the riboflavin-producing strains. The study thus represents a convenient and efficient method for selection of novel riboflavin producers. These riboflavin(+) strains thus identified and characterized could be explored as potent candidates for the development of a wide range of dairy- and cereal-based foods for the delivery of in situ riboflavin to consumers.

Lactic acid bacteria as a cell factory for riboflavin production.

Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for riboflavin biosynthesis by lactic acid bacteria are discussed. Genetically modified strains by employing genetic engineering and chemical analogues have been developed to enhance riboflavin production. The present review attempts to collect the currently available information on riboflavin production by microbes in general, while placing greater emphasis on food grade lactic acid bacteria and human gut commensals. For designing riboflavin-enriched functional foods, proper selection and exploitation of riboflavin-producing lactic acid bacteria is essential. Moreover, eliminating the in situ vitamin fortification step will decrease the cost of food production.

Food protein-derived bioactive peptides in management of type 2 diabetes.

BACKGROUND: Type 2 diabetes (T2D), one of the major common human health problems, is growing at an alarming rate around the globe. Alpha-glucosidase and dipeptidyl peptidase IV (DPP-IV) enzymes play a significant role in development of T2D. Hence, reduction or inhibition of their activity can be one of the important strategies in management of T2D. Studies in the field of bioactive peptides have shown that dietary proteins could be natural source of alpha-glucosidase and DPP-IV inhibitory peptides. PURPOSE: The purpose of this review is to provide an overview of food protein-derived peptides as potential inhibitors of alpha-glucosidase and DPP-IV with major focus on milk proteins. METHODS: Efforts have been made to review the available information in literature on the relationship between food protein-derived peptides and T2D. This review summarizes the current data on alpha-glucosidase and dipeptidyl peptidase IV inhibitory bioactive peptides derived from proteins and examines the potential value of these peptides in the treatment and prevention of T2D. In addition, the proposed modes of inhibition of peptide inhibitors are also discussed. RESULTS: Studies revealed that milk and other food proteins-derived bioactive peptides play a vital role in controlling T2D through several mechanisms, such as the satiety response, regulation of incretin hormones, insulinemia levels, and reducing the activity of carbohydrate degrading digestive enzymes. CONCLUSIONS: The bioactive peptides could be used in prevention and management of T2D through functional foods or nutraceutical supplements. Further clinical trials are necessary to validate the findings of in vitro studies and to confirm the efficiency of these peptides for applications.

"Potential health benefits of lunasin: a multifaceted soy-derived bioactive peptide".

Bioactive peptides are small protein fragments derived from enzymatic hydrolysis of food proteins, fermentation with proteolytic starter cultures, and gastrointestinal digestion. These peptides have positive impacts on a number of physiological functions in living beings. Lunasin, a soy-derived bioactive peptide, is one of the most promising among them. Lunasin encoded within 2S albumin (GM2S-1) gene, identified as a novel peptide extracted from soybean seed. It is composed of 43 amino acid residues with a molecular weight of 5.5 kDa. Extensive scientific studies have shown that lunasin possesses inherent antioxidative, anti-inflammatory, anticancerous properties and could also play a vital role in regulating of cholesterol biosynthesis in the body. Its high bioavailability and heat stable nature allow its potential use as dietary supplement. The present review summarizes some of the potential health and therapeutic benefits of lunasin reported hitherto.

Determination of folate/folic acid level in milk by microbiological assay, immuno assay and high performance liquid chromatography.

A concurrent determination of folate versus folic acid in milk by microbiological assay (MA) with Lactobacillus rhamnosus as the assay organism, Enzyme Linked Immuno Sorbent Assay (ELISA) by competitive binding rapid ELISA kit (RIDASCREEN®) and high-pressure-liquid chromatography (HPLC) was done for detection of the folate form and its level. MA gave total folate content as Lb. rhamnosus showed similar response to most folate isomers formed by the tri-enzyme treatment in comparison with the other two methods which specifically estimated the folic acid. In case of ELISA, specificity was apparently limited to folic acid and dihydro folic acid and thereby showed a lower response for other folate derivatives. Estimation by HPLC with UV detector was highly specific and hence only folic acid could be detected without any cross reactivity. Among the different methods HPLC was observed to be the most sensitive method for determination of folic acid and hence can efficiently determine the folic acid fortification level while MA remained highly efficient, sensitive and reproducible method for estimation of total folate indicating its potential use for dietary folate estimation.

Current status and emerging role of glutathione in food grade lactic acid bacteria.

Lactic acid bacteria (LAB) have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms.

Multifaceted attributes of dairy propionibacteria: a review.

Dairy propionibacteria are Generally Recognized as Safe (GRAS) status microorganisms which have been traditionally used for the manufacture of Swiss type cheeses. In the last two decades various added features and functionalities have been discovered and developed from these bacteria. Propionibacteria are robust organisms with remarkable adaptability to technological and physiological stress conditions. Besides, they also display a multitude of health promoting properties like modulation of gut microbiota, improved gut physiology and immunomodulation suggesting their promising probiotic potential. Propionibacteria produce an interestingly wide range of functional biomolecules like B group vitamins, trehalose, conjugated linoleic acid, propionic acid, bacteriocins, bifidogenic factors etc. These bacteria are thus now being explored for designing novel functional foods as well as for industrial production of nutraceuticals. Growing interest in these bacteria is fueled by the first whole genome sequencing of a Propionibacterium freudenreichii strain providing a platform for better understanding of various pathways and further improvement in related process technologies.

Response surface optimization of the cultivation conditions and medium components for the production of folate by Streptococcus thermophilus.

Optimization of the cultivation conditions and medium components for folate production by the highest folate producing Streptococcus thermophilus strain RD102 was carried out using a 23 central composite design and surface modelling method of response surface methodology. As folate production was observed to be growth-associated, hence the desired responses selected for the optimization were both folate production and growth. The selected factors based on preliminary investigations were incubation period, concentrations of p-amino benzoic acid (PABA) the growth precursor, and lactose as carbon source. The optimum concentrations of PABA and lactose were found to be 300 micropm and 3% respectively at 72 h incubation. The optimized conditions resulted in an increase in folate production by 26% compared with control conditions (0% PABA and lactose at 37 degrees C). Using the method of experimental factorial design and response surface analysis, it was possible to determine optimal operating conditions to obtain a higher folate production by Strep. thermophilus. Therefore, this study constitutes a step in developing strategies to modulate the folate level to a higher level.