Lignocellulosic materials are among the most promising alternative energy resources that can be utilized to produce cellulosic ethanol. However, the physical and chemical structure of lignocellulosic materials forms strong native recalcitrance and results in relatively low yield of ethanol from raw lignocellulosic materials. An appropriate pretreatment method is required to overcome this recalcitrance. For decades various pretreatment processes have been developed to improve the digestibility of lignocellulosic biomass. Each pretreatment process has a different specificity on altering the physical and chemical structure of lignocellulosic materials. In this paper, the chemical structure of lignocellulosic biomass and factors likely affect the digestibility of lignocellulosic materials are discussed, and then an overview about the most important pretreatment processes available are provided. In particular, the combined pretreatment strategies are reviewed for improving the enzymatic hydrolysis of lignocellulose and realizing the comprehensive utilization of lignocellulosic materials.

The role of pretreatment in improving the enzymatic hydrolysis

Background: Demand for healthy and safe food with minimal use of synthetic inputs (including synthetic preservatives) is increasing rapidly. Plastic polymers being hazardous to the environment, sig ...

Chitosan based nanocomposite films and coatings: Emerging antimicrobial food packaging alternatives

Salinity stress is one of the major abiotic stresses threatening sustainable crop production worldwide. The extent of salinity affected area is expected to cover about 50% of total agricultural land by 2050. Salinity stress produces various detrimental effects on plants' physiological, biochemical, and molecular features and reduces productivity. The poor plant growth under salinity stress is due to reduced nutrient mobilization, hormonal imbalance, and formation of reactive oxygen species (ROS), ionic toxicity, and osmotic stress. Additionally, salinity also modulates physicochemical properties and reduces the microbial diversity of soil and thus decreases soil health. On the other hand, the demand for crop production is expected to increase in coming decades owing to the increasing global population. Conventional agricultural practices and improved salt-tolerant crop varieties will not be sufficient to achieve the yields desired in the near future. Plants harbor diverse microbes in their rhizosphere, and these have the potential to cope with the salinity stress. These salinity-tolerant plant growth-promoting bacteria (PGPB) assist the plants in withstanding saline conditions. These plant-associated microbes produce different compounds such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3-acetic acid (IAA), antioxidants, extracellular polymeric substance (EPS), and volatile organic compounds (VOC). Additionally, the naturally associated microbiome of plants has the potential to protect the host through stress avoidance, tolerance, and resistance strategies. Recent developments in microbiome research have shown ways in which novel microbe-assisted technologies can enhance plant salt tolerance and enable higher crop production under saline conditions. This focused review article presents the global scenario of salinity stress and discusses research highlights regarding PGPB and the microbiome as a biological tool for mitigation of salinity stress in plants.

/pdf/plant-growth-promoting-bacteria-biological-tools-for-the-3nz0fqnz2y.pdf

Plant Growth-Promoting Bacteria: Biological Tools for the Mitigation of Salinity Stress in Plants

Print me an organ! Why we are not there yet

Hydrolyzed collagen (HC) is a group of peptides with low molecular weight (3–6 KDa) that can be obtained by enzymatic action in acid or alkaline media at a specific incubation temperature. HC can be extracted from different sources such as bovine or porcine. These sources have presented health limitations in the last years. Recently research has shown good properties of the HC found in skin, scale, and bones from marine sources. Type and source of extraction are the main factors that affect HC properties, such as molecular weight of the peptide chain, solubility, and functional activity. HC is widely used in several industries including food, pharmaceutical, cosmetic, biomedical, and leather industries. The present review presents the different types of HC, sources of extraction, and their applications as a biomaterial.

Hydrolyzed Collagen-Sources and Applications.

Plastic biodegradation: Frontline microbes and their enzymes

Skin of Centrolophus niger (black ruff) commonly referred as Medusa, is used for the extraction of Acid Soluble Collagen. This is the first report of collagen extraction from skin of black ruff where lactic acid with 45% yield proved to be efficient solvent. SDS-PAGE, UV visible absorbance, FT-IR and SEM analysis confirmed that extracted collagen is native type I. Extracted collagen showed emulsifying activity index as 20.24 m2 g−1 and emulsion stability index of 15.86 min. Collagen was used for the preparation of collagen-chitosan film which could be used for food packaging purpose. Film incorporated with 5% pomegranate peel extract declined solubility in water remarkably and showed antibacterial effect against food borne pathogens like Bacillus saprophyticus LNB 333F5, Bacillus subtilis NCIM 2635, Salmonella typhi NCIM 2501 and Escherichia coli NCIM 2832. Thus, present study deals with extraction and characterization of collagen from fish waste and its application in the development of antibacterial active food packaging film.

Extraction and characterization of acid soluble collagen from fish waste: Development of collagen-chitosan blend as food packaging film

Collagen has enormous applications in food, biomedical and pharmaceutical industries; but its high cost severely limits its use. Fish processing waste is a promising and cost efficacious source of collagen, which otherwise stated as an earnest environmental pollutant. Carp (Cyprinus carpio) is one of the main species of freshwater fish consumed in India. Acid-soluble collagen (ASC) was isolated from scales of Cyprinus carpio. Scales were demineralized by EDTA treatment and ASC was extracted from the demineralized scales. The yield of scale ASC was 9.79% (on the wet weight basis). SDS–PAGE and FTIR corroborated the isolated protein as collagen. Denaturation temperature (Td) of isolated collagen was found to be 37 °C. Considering bioactive properties of collagen, a milk based food product – paneer was developed by incorporation of the extracted collagen. Composed paneer was found to be acceptable with good sensorial and textural attributes. Same scales were further treated enzymatically and the released metabolites were tested for their competency to promote the plant growth. Released metabolites showed excellent plant growth promotion and hence could be successfully employed as an economic source of nitrogen fertilizers for plants.

Isolation, characterization and valorizable applications of fish scale collagen in food and agriculture industries

Despite of having enormous applications, the use of collagen is predominantly limited because of its high cost. Most of the mammalian sources used for its production have major drawbacks. However, compared to mammalian sources, fish waste can be utilized as cost-effective alternative to produce collagen. Around 75% part of fish is discarded as a waste which contains high concentration of collagen. Fish collagen has multiple advantages over mammalian collagen and hence can be a promising alternative for it. Proteases with collagenolytic activities are also of immense importance because of their industrial as well as biological applications. Microbial collagenolytic proteases are gaining huge attention in these days because of their lower requirements and higher productivity. They perform important role in global recycling of collagenous waste. This review gives recent information on collagen and collagenolytic proteases. Here, utilization of seafood by-products is discussed to recover the collagen and its recent applications are summarized. In addition to this, current review also highlights the recent status of collagenases in which present strategies and new technology used for the isolation, screening, production optimization, purification, characterization and applications of microbial collagenases are discussed.

Prashant K. Bhagwat

Papers

Plastic biodegradation: Frontline microbes and their enzymes

Extraction and characterization of acid soluble collagen from fish waste: Development of collagen-chitosan blend as food packaging film

Isolation, characterization and valorizable applications of fish scale collagen in food and agriculture industries

Collagen and collagenolytic proteases: A review

Improved synthesis of copper oxide nanosheets and its application in development of supercapacitor and antimicrobial agents