Cellulase Production from Species of Fungi and Bacteria from Agricultural Wastes and Its Utilization in Industry: A Review

In energy deficient world, cellulases play a major role for the production of alternative energy resources utilizing lignocellulosic waste materials for bioethanol and biogas production. This study highlights fungal and bacterial strains for the production of cellulases and its industrial applications. Solid State Fermentation (SSF) is more suitable process for cellulase production as compared to submerge fermentation techniques. Fungal cellulosomes system for the production of cellulases is more desirable and resistant to harsh environmental conditions. Trichoderma species are considered as most suitable candidate for cellulase production and utilization in industry as compared to Aspergillus and Humicola species. However, genetically modified strains of Aspergillus have capability to produce cellulase in relatively higher amount. Bacterial cellulase are more resistant to alkaline and thermophile conditions and good candidate in laundries. Cellulases are used in variety of industries such as textile, detergents and laundries, food industry, paper and pulp industry and biofuel production. Thermally stable modified strains of fungi and bacteria are good future prospect for cellulase production.

Optimization of Cellulose Nanocrystal Isolation from Ayous Sawdust Using Response Surface Methodology

This study focuses on the extraction of cellulose nanocrystals (CNC), from microcrystalline cellulose (MCC), derived from Ayous sawdust. The process involves multiple steps and a large amount of chemical products. The objective of this research was to determine the effects of factors that impact the isolation process and to identify the optimal conditions for CNC isolation by using the response surface methodology. The factors that varied during the process were the quantity of MCC, the concentration of sulfuric acid, the hydrolysis time and temperature, and the ultrasonic treatment time. The response measured was the yield. The study found that with 5.80 g of microcrystalline cellulose, a sulfuric acid concentration of 63.50% (w/w), a hydrolysis time of 53 minutes, a hydrolysis temperature of 69˚C, and a sonication time of 19 minutes are the ideal conditions for isolation. The experimental yield achieved was (37.84 ± 0.99) %. The main factors influencing the process were the sulfuric acid concentration, hydrolysis time and temperature, with a significant influence (p < 0.05). Infrared characterization results showed that nanocrystals were indeed isolated. With a crystallinity of 35.23 and 79.74, respectively, for Ayous wood fiber and nanocrystalline cellulose were observed by X-ray diffraction, with the formation of type II cellulose, thermodynamically more stable than native cellulose type I.

Application of cellulase in producing reducing sugar with waste lignocellulosic

The cellulase expands the use of waste lignocellulosic and improves the feasibility of ethanol production with waste lignocellulosic. In this paper the types, mechanisms of cellulase and its application in reducing sugar production were presented in detail. The strains that produce cellulase and methods for improving the cellulase activity in reducing sugar production with waste lignocellulosic were described.

A Technological Overview of Biogas Production from Biowaste

The current irrational use of fossil fuels and the impact of greenhouse gases on the environment are driving research into renewable energy production from organic resources and waste. The global energy demand is high, and most of this energy is produced from fossil resources. Recent studies report that anaerobic di- gestion （AD） is an efficient alternative technology that combines biofuel production with sustainable waste management, and various technological trends exist in the biogas industry that enhance the production and quality of biogas. Further investments in AD are expected to meet with increasing success due to the low cost of available feedstocks and the wide range of uses for biogas （i.e., for heating, electricity, and fuel）. Bio- gas production is growing in the European energy market and offers an economical alternative for bioenergy production. The objective of this work is to provide an overview of biogas production from lignocellulosic waste, thus providing information toward crucial issues in the biogas economy.

Obtaining Bioethanol through Hydrolytic Treatment of Agro-Industrial Banana Residues

The banana is a food of great importance and it is consumed in almost the entire world. However, its harvest generates large quantities of mostly lignocellulosic waste, which can be used for the production of biofuels such as bioethanol. In this work, the potential for bioethanol production from agro-industrial plantain crop residues was evaluated with different operating conditions. A 24?experimental design was used, having as study variables: time of hydrolysis, pH of hydrolysis, concentration time, and fermentation time. The samples used were scraps consisting of a mixture of stems, leaves, and banana peels. The bioethanol obtained was characterized by physicochemical properties such as density, refractive index, and FTIR. As a result, it was obtained that the volume of bioethanol represented higher yields;using NaOH as a hydrolyzing agent, with hydrolysis time of 30 minutes, high fermentation time, and low concentrations. The chemical characterization of banana agro-industrial waste indicated that, the raw material could be considered as a potential source for bioethanol production, since it has a high content of cellulose.

Research progress on hydrothermal dissolution and hydrolysis of lignocellulose and lignocellulosic waste

Ethanol production from lignocellulosic waste has attracted considerable attention because of its feasi- bility and the generation of valuable products. Previous studies have shown that pretreatment and hydrolysis are key processes for lignocellulose conversion. Hydrothermal process is a promising technique because of its efficiency to break down the lignocellulosic structures and produce fermentable hexoses. Most studies in this field have therefore focused on understanding these processes or optimizing the parameters, but commonly reported low yields of fermentable hexoses. The inability to produce high yields of fermentable hexoses is mainly attributed to inadequate information on the conversion mechanisms of lignocellulose, particularly the reaction rules of dissolu- tion, which is a limiting step in the entire conversion process. This paper critically reviewed the progress done in the research and development of the hydrothermal dissolution and hydrolysis of lignocellulose. Principles, processes, and related studies on separate dissolution and asynchronous hydrolysis of lignin, hemieellulose, and cellulose are presented. Potential research prospects are also suggested.

Fermentative bio-hydrogen production using lignocellulosic waste biomass:a revie

Solid waste management needs,increasing pollution level by burning or dumping of waste,and the use of fossil fuels and depleting energy resources are a few of the problems of the decade that need to find answers.Disposal of lots of compound polymers-rich biomass waste is done worldwide by dumping on land or into water bodies or else by incineration or long-term storage in an available facility commonly.This kind of disposal instead becomes a reason to add the soil,water,and air pollution.A lot of multidisciplinary collaboration in different streams of science and technology has added to the efficiency of using such waste for use as an alternative energy form,like biogas and biohydrogen.The use of biogas plants for converting biological waste into methane using municipal solid waste(MSW)is known since a long time.Along with MSW,a lot of other agricultural waste and kitchen waste are also added every day to nature.But the complex components of such waste material like lignocellulosic wastes still don’t pass the test of qualifying as a resource for biogas and even more energy-efficient and cleaner biofuel,bio-hydrogen.It may be because of its complicated structure and a lot of parameters that affect its use for converting it into bio-hydrogen.This review is designed to analyze and compare these parameters for optimum lignocellulosic waste conversion,more specifically agriculture and food waste,into cleaner energy forms that would help to tackle the solid waste management and air pollution control more effectively.