Aspergillus spp., a versatile cell factory for enzymes and metabolites: Interventions through genome editing

Aspergillus sp. is widely distributed in nature and plays significant roles in the degradation of lignocellulose biomass and extensively used in bioprocess and fermentation technology and many species are also a generally regarded safe. Many of the Aspergillus species are established cell factories due to their inherent capacity in secreting large number of hydrolytic enzymes. With the advent of next generation genomic technologies and metabolic engineering technologies, the production potential of Aspergillus cell factory has improved over the years. Various genome editing tools has been developed for Aspergillus like engineered nucleases, zinc finger nucleases, TALEN and CRISPR-Cas9 system. Currently, the CRISPR/Cas9-based technique is extensively used to enhance the effectiveness of gene manipulation in model system Aspergillus nidulans and other strains like Aspergillus oryzae, Aspergillus niger and Aspergillus fumigatus. This review describes the recent developments of genome editing technologies in Aspergillus the synthesis of heterologous proteins and secondary metabolites in the Aspergillus species

Bioconversion of waste cooking oil for the production of poly-3-hydroxybutyrate using Bacillus cereus MPTDC

557-562Used cooking oil is generated as a byproduct during frying process. It cannot be reused for cooking process due to health issues such as cancer and other digestive disorders. Alternative strategy is utilization of this waste cooking oil for production of poly-3-hydroxybutyrate (PHB) a biopolymer which can be used as a substitute for petroleum derived plastics or other value added products. In the present investigation, we used waste cooking oil as carbon source for PHB production by Bacillus cereus MPTDC. The optimum conditions of PHB production by Bacillus cereus MPTDC were waste cooking oil concentration of 2% (v/v), incubation time of 96 h, ammonium sulphate concentration of 7.5% and yeast extract concentration of 0.2%. Under optimized conditions the strain produced 3.777 g/L of PHB. The results indicate the potential of used cooking oil as carbon source for PHB production by Bacillus cereus MPTDC

Bioconversion of waste cooking oil for the production of poly-3-hydroxybutyrate using Bacillus cereus MPTDC

Used cooking oil is generated as a byproduct during frying process. It cannot be reused for cooking process due to health issues such as cancer and other digestive disorders. Alternative strategy is utilization of this waste cooking oil for production of poly-3-hydroxybutyrate (PHB) a biopolymer which can be used as a substitute for petroleum derived plastics [ABG1] or other value added products. In the present investigation, we used waste cooking oil as carbon source for PHB production by Bacillus cereus MPTDC. The optimum conditions of PHB production by Bacillus cereus MPTDC were waste cooking oil concentration of 2% (v/v), incubation time of 96 h, ammonium sulphate concentration of 7.5% and yeast extract concentration of 0.2%. Under optimized conditions the strain produced 3.777 g/L of PHB. The results indicate the potential of used cooking oil as carbon source for PHB production by Bacillus cereus MPTDC

Applications of Microbial Enzymes in Food Industry

Uporaba enzima i mikroorganizama za pripremu hrane poznata je od davnina. S napretkom tehnologije razvijeni su novi enzimi specifičnih svojstava i širokog raspona primjene, te se neprestano traga za novim mogućnostima njihove uporabe. Bakterije, kvasci i gljivice te njihovi enzimi često se upotrebljavaju za pripremu hrane poboljšanog okusa i teksture, a ekonomski su isplativi. Mikrobni enzimi se koriste u većoj mjeri nego biljni i životinjski enzimi, i to zbog jednostavnije i jeftinije proizvodnje te njihove postojane kvalitete. U ovom se revijalnom prikazu raspravlja o najnovijim postignućima u tehnologiji proizvodnje enzima u prehrambenoj industriji. Naveden je opsežan popis enzima koji se koriste za obradu hrane, mikroorganizama iz kojih su proizvedeni, te je dan pregled njihove raznovrsne primjene.The use of enzymes or microorganisms in food preparations is an age-old process. With the advancement of technology, novel enzymes with wide range of applications and specificity have been developed and new application areas are still being explored. Microorganisms such as bacteria, yeast and fungi and their enzymes are widely used in several food preparations for improving the taste and texture and they offer huge economic benefits to industries. Microbial enzymes are the preferred source to plants or animals due to several advantages such as easy, cost-effective and consistent production. The present review discusses the recent advancement in enzyme technology for food industries. A comprehensive list of enzymes used in food processing, the microbial source of these enzymes and the wide range of their application are discussed

Advances in Biofuel Production by Strain Development in Yeast from Lignocellulosic Biomass

The development of biorefineries directed to the production of fuels, chemicals, and energy is important to reduce economic dependence and environmental impacts of a petroleum‐based economy. The last two decades have witnessed a fast industrialization and the surge in the energy demands that has compelled the energy sector to think beyond fossil fuels. The energy crisis and the need for a sustainable environment development shifted the energy spectrum toward biomass‐based renewable energy generation. Alternate fuels like lignocellulosic ethanol can be produced and used for blending in gasoline and other applications for sustainable development. Saccharomyces sp. has been a fascinating yeast for fermentation processes since Ancient Greece, where it was used for wine making. There are several technical challenges with commonly used Saccharomyces sp. including: (i) does not convert pentose sugars; (ii) has low tolerance to alcohols, acids, and solvents; (iii) is very sensitive to inhibitors (e.g., furfural, 5‐hydroxymethylfurfural, aromatics, etc.) generated during hydrolysis of agrowastes; and (iv) has fermentative stresses (e.g., pH). These limitations obstruct the process when agro‐waste is used as a feedstock for biofuel production. These challenges can be overcome by taking systems approaches using state‐of‐the‐art tools of systems biology, synthetic biology, and evolutionary engineering in the context of industrial bioprocess along with strain adaptation strategies. This chapter focuses on recent developments of yeast biotechnology by strain adaptation and strain development

Synthetic Biology and Metabolic Engineering Approaches and Its Impact on Non-Conventional Yeast and Biofuel Production

The increasing fossil fuel scarcity has led to an urgent need to develop alternative fuels. Currently microorganisms have been extensively used for the production of first-generation biofuels from lignocellulosic biomass. Yeast is the efficient producer of bioethanol among all existing biofuels option. Tools of synthetic biology have revolutionized the field of microbial cell factories especially in the case of ethanol and fatty acid production. Most of the synthetic biology tools have been developed for the industrial workhorse Saccharomyces cerevisiae. The non-conventional yeast systems have several beneficial traits like ethanol tolerance, thermotolerance, inhibitor tolerance, genetic diversity, etc., and synthetic biology have the power to expand these traits. Currently, synthetic biology is slowly widening to the non-conventional yeasts like Hansenula polymorpha, Kluyveromyces lactis, Pichia pastoris, and Yarrowia lipolytica. Herein, we review the basic synthetic biology tools that can apply to non-conventional yeasts. Furthermore, we discuss the recent advances employed to develop efficient biofuel-producing non-conventional yeast strains by metabolic engineering and synthetic biology with recent examples. Looking forward, future synthetic engineering tools’ development and application should focus on unexplored non-conventional yeast species

Recent advances in the production of value added chemicals and lipids utilizing biodiesel industry generated crude glycerol as a substrate - Metabolic aspects, challenges and possibilities: An overview

One of the major ecological concerns associated with biodiesel production is the generation of waste/ crude glycerol during the trans-esterification process. Purification of this crude glycerol is not economically viable. In this context, the development of an efficient and economically viable strategy would be biotransformation reactions converting the biodiesel derived crude glycerol into value added chemicals. Hence the process ensures the sustainability and waste management in biodiesel industry, paving a path to integrated biorefineries. This review addresses a waste to wealth approach for utilization of crude glycerol in the production of value added chemicals, current trends, challenges, future perspectives, metabolic approaches and the genetic tools developed for the improved synthesis over wild type microorganisms were described

Water hyacinth a potential source for value addition: An overview

Water hyacinth a fresh water aquatic plant is considered as a noxious weed in many parts of the world since it grows very fast and depletes nutrients and oxygen from water bodies adversely affecting the growth of both plants and animals. Hence conversion of this problematic weed to value added chemicals and fuels helps in the self-sustainability especially for developing countries. The present review discusses the various value added products and fuels which can be produced from water hyacinth, the recent research and developmental activities on the bioconversion of water hyacinth for the production of fuels and value added products as well as its possibilities and challenges in commercialization. (C) 2017 Elsevier Ltd. All rights reserved

Lignocellulose in future biorefineries: strategies for cost-effective production of biomaterials and bioenergy

Lignocellulosic biomass has been emerging as a biorefinery precursor for variety of biofuels, platform chemicals and biomaterials because of its specific surface morphology, exceptional physical, chemical and biological characteristics. The selection of proper raw materials, integration of nano biotechnological aspects, and designing of viable processes are important to attain a cost-effective route for the development of valuable end products. Lignocellulose-based materials can prove to be outstanding in terms of techno-economic viability, as well as being environmentally friendly and reducing effluent load. This review should facilitate the identification of better lignocellulosic sources, advanced pretreatments, and production of value-added products in order to boost the future industries in a cleaner and safer way

Probiotics and gut microbiome-Prospects and challenges in remediating heavy metal toxicity

The gut microbiome, often referred to as "super organ", comprises up to a hundred trillion microorganisms, and the species diversity may vary from person to person. They perform a decisive role in diverse biological functions related to metabolism, immunity and neurological responses. However, the microbiome is sensitive to environmental pollutants, especially heavy metals. There is continuous interaction between heavy metals and the microbiome. Heavy metal exposure retards the growth and changes the structure of the phyla involved in the gut microbiome. Meanwhile, the gut microbiome tries to detoxify the heavy metals by altering the physiological conditions, intestinal permeability, enhancing enzymes for metabolizing heavy metals. This review summarizes the effect of heavy metals in altering the gut microbiome, the mechanism by which gut microbiota detoxifies heavy metals, diseases developed due to heavy metal-induced dysbiosis of the gut microbiome, and the usage of probiotics along with advancements in developing improved recombinant probiotic strains for the remediation of heavy metal toxicity