Monica Puniya

Biological and medicinal properties of grapes and their bioactive constituents: an update.

The grape is one of the most valued conventional fruits, worldwide. Although most of the parts of the grapevine are useful, primarily, the grape is considered as a source of unique natural products not only for the development of valuable medicines against a number of diseases, but also for manufacturing various industrial products. Over the last few decades, apart from the chemistry of grape compounds, considerable progress has been made towards exploring the biological activities of various grape-derived constituents. Today, it is well established that in addition to serving as food, the grape is a major source of several phytochemicals. The main biologically active and well-characterized constituent from the grape is resveratrol, which is known for various medicinal properties in human diseases. This review discusses the roles of various grape-derived phytochemicals in relation to various diseases.

New aspects and strategies for methane mitigation from ruminants

The growing demand for sustainable animal production is compelling researchers to explore the potential approaches to reduce emissions of greenhouse gases from livestock that are mainly produced by enteric fermentation. Some potential solutions, for instance, the use of chemical inhibitors to reduce methanogenesis, are not feasible in routine use due to their toxicity to ruminants, inhibition of efficient rumen function or other transitory effects. Strategies, such as use of plant secondary metabolites and dietary manipulations have emerged to reduce the methane emission, but these still require extensive research before these can be recommended and deployed in the livestock industry sector. Furthermore, immunization vaccines for methanogens and phages are also under investigation for mitigation of enteric methanogenesis. The increasing knowledge of methanogenic diversity in rumen, DNA sequencing technologies and bioinformatics have paved the way for chemogenomic strategies by targeting methane producers. Chemogenomics will help in finding target enzymes and proteins, which will further assist in the screening of natural as well chemical inhibitors. The construction of a methanogenic gene catalogue through these approaches is an attainable objective. This will lead to understand the microbiome function, its relation with the host and feeds, and therefore, will form the basis of practically viable and eco-friendly methane mitigation approaches, while improving the ruminant productivity.

Gut Microbiota Modulation and Its Relationship with Obesity Using Prebiotic Fibers and Probiotics: A Review

In the present world scenario, obesity has almost attained the level of a pandemic and is progressing at a rapid rate. This disease is the mother of all other metabolic disorders, which apart from placing an added financial burden on the concerned patient also has a negative impact on his/her well-being and health in the society. Among the various plausible factors for the development of obesity, the role of gut microbiota is very crucial. In general, the gut of an individual is inhabited by trillions of microbes that play a significant role in host energy homeostasis by their symbiotic interactions. Dysbiosis in gut microbiota causes disequilibrium in energy homeostasis that ultimately leads to obesity. Numerous mechanisms have been reported by which gut microbiota induces obesity in experimental models. However, which microbial community is directly linked to obesity is still unknown due to the complex nature of gut microbiota. Prebiotics and probiotics are the safer and effective dietary substances available, which can therapeutically alter the gut microbiota of the host. In this review, an effort was made to discuss the current mechanisms through which gut microbiota interacts with host energy metabolism in the context of obesity. Further, the therapeutic approaches (prebiotics/probiotics) that helped in positively altering the gut microbiota were discussed by taking experimental evidence from animal and human studies. In the closing statement, the challenges and future tasks within the field were discussed.

Role of live microbial feed supplements with reference to anaerobic fungi in ruminant productivity: A review

Abstract To keep the concept of a safe food supply to the consumers, animal feed industries world over are showing an increasing interest in the direct-fed microbials (DFM) for improved animal performance in terms of growth or productivity. This becomes all the more essential in a situation, where a number of the residues of antibiotics and/or other growth stimulants reach in milk and meat with a number of associated potential risks for the consumers. Hence, in the absence of growth stimulants, a positive manipulation of the rumen microbial ecosystem to enhance the feedstuff utilization for improved production efficiency by ruminants has become of much interest to the researchers and entrepreneurs. A few genera of live microbes (i.e., bacteria, fungi and yeasts in different types of formulations from paste to powder) are infrequently used as DFM for the domestic ruminants. These DFM products are live microbial feed supplements containing naturally occurring microbes in the rumen. Among different DFM possibilities, anaerobic rumen fungi (ARF) based additives have been found to improve ruminant productivity consistently during feeding trials. Administration of ARF during the few trials conducted, led to the increased weight gain, milk production, and total tract digestibility of feed components in ruminants. Anaerobic fungi in the rumen display very strong cell-wall degrading cellulolytic and xylanolytic activities through rhizoid development, resulting in the physical disruption of feed structure paving the way for bacterial action. Significant improvements in the fiber digestibility were found to coincide with increases in ARF in the rumen indicating their role. Most of the researches based on DFM have indicated a positive response in nutrient digestion and methane reducing potential during in vivo and/or in vitro supplementation of ARF as DFM. Therefore, DFM especially ARF will gain popularity but it is necessary that all the strains are thoroughly studied for their beneficial properties to have a confirmed ‘generally regarded as safe’ status for ruminants.

Enumeration of methanogens with a focus on fluorescence in situ hybridization

Methanogens, the members of domain Archaea are potent contributors in global warming. Being confined to the strict anaerobic environment, their direct cultivation as pure culture is quite difficult. Therefore, a range of culture-independent methods have been developed to investigate their numbers, substrate uptake patterns, and identification in complex microbial communities. Unlike other approaches, fluorescence in situ hybridization (FISH) is not only used for faster quantification and accurate identification but also to reveal the physiological properties and spatiotemporal dynamics of methanogens in their natural environment. Aside from the methodological aspects and application of FISH, this review also focuses on culture-dependent and -independent techniques employed in enumerating methanogens along with associated problems. In addition, the combination of FISH with micro-autoradiography that could also be an important tool in investigating the activities of methanogens is also discussed.

‘Omics’ Approaches to Understand and Manipulate Rumen Microbial Function

Diverse populations of rumen microorganisms in gut contribute to develop ability of breaking down fibrous foods, which are mostly unusable by humans (Owens FN, Goetsch AL (1988) Ruminal fermentation. In: Church DC (ed) The ruminant animal, digestive physiology and nutrition. Prentice-Hall, Englewood Cliffs, p 160). Rumen is having a larger population of microorganisms, more than a trillion organisms and wide diversity (hundreds of species and thousands of subspecies), per ounce of rumen contents (Xu et al., J Anim Sci 85:1024–1029, 2007). There are various traditional approaches through which overall performance of the rumen has been attempted to improve, e.g. plant secondary metabolites, microbial feed additives, chemical feed additives, selective stimulation of beneficial rumen microbes and selective inhibition of harmful rumen microbes. In spite of these, nowadays various new approaches are being used to improve our understanding of the relationships among the various rumen microorganisms and towards how they interact with their hosts (Chaucheyras-Durand and Ossa, Prof Anim Sci 30:1–12, 2014). To better characterize species in the rumen, new advanced technological aids such as gene sequencing and study of gene (genomics), protein (proteomics) and metabolite (metabolomics) expression are being frequently used. This chapter will majorly emphasize on recent tools used in exploring the diversity of rumen.