Conversion of food and kitchen waste to value-added products

Circular bioeconomy strategies: From scientific research to commercially viable products

Sustainability is a major goal for the country development without negative effects on climate change, allied to scarcity and instability in the fossil fuels prices, makes attractive the use of several agricultural, forestry and industrial biomass which may undergo combustion processes for the production of renewable energy, either in its in natural form, pressed into dense pellets or briquettes, or after thermochemical conversion through gasification, pyrolysis, liquefaction, carbonization, and torrefaction. The aim of the current research was to identify the major environmental, economic and social impacts arising from the solid fossil fuels, as well as introduce a technical approach to address the scenario of the main energy crops produced in Brazil, wastes arising from the same, their quantification, and alternatives to using such wastes in the solid biofuels production. Moreover, it was intended to describe the current national and global market, policies, advantages, and challenges by using biofuels, in comparison with fossil fuels.

Scenarios and prospects of solid biofuel use in Brazil

A study on cellulase production from a mixture of lignocellulosic wastes

The most promising way to achieve the smooth, flexible and sustainable bioeconomy is the utilization of renewable lignocellulosic biomass as a feedstock for the production of fuels, chemicals, enzymes and high-valued products. Cellulolytic enzymes are indispensable for the maintenance of global carbon cycle, since they catalyze the degradation of cellulose. Therefore for solving the forthcoming waste management and energy issues of mankind, cellulase production technology plays significant and vital role. Cellulases are industrial enzymes and have extensive application in various process industries. Its relatively high cost of production has hindered the wider industrial application. Significant cost reduction is required to enhance the commercial viability of cellulase production technology. Utilization of novel and cheap lignocellulosic renewable resources as substrate for enzyme fermentation process is a promising way of efficient and low cost cellulases production. The present paper reveals, a review on cellulase production through various microorganisms employing economical, abundantly available renewable lignocellulosic biomass as carbon source. It also deals with the recent approaches used at microbial as well as feedstock level, making more efficient, flexible and cost effective fermentation process.

Valorization of Waste Biomass in Fermentative Production of Cellulases: A Review

Cellulase has by vast applications in the biofuel, pulp and paper, detergent and textile industries. The three components of the enzyme complex (endoglucanase, exoglucanase and β-glucosidase) can effectively depolymerize the cellulose chains in lignocellulosic substrate. Solid-state fermentation (SSF) by fungi is a preferable production route for cellulase because of its low cost, among other advantages. This work describes the cellulase production by Aspergillus niger NRRL3 grown on SSF. SSF was carried out on soybean hulls and waste paper as supports. The effect of the support on cellulase production was assessed under a completely randomized factorial design. The support-time interaction was significant for all the variables studied. Both materials were characterized in terms of water absorption index and critical humidity point. Samples of culture were analyzed with scanning electron microscopy (SEM) to study spores and fungal growth. Maximum endoglucanase activity was found at 96 h using soybean hulls as support (5914.29 U L−1), being four times higher than that obtained using waste paper at the same fermentation time. The exoglucanase activity in soybean hulls was maximal at 96 h (4551.19 U L−1), being 9.6 times higher than that obtained in waste paper at the same time. The maximum β-glucosidase activity in soybean hulls (984.01 U L−1) was reached at 96 h, being 1.7 times greater than that obtained in waste paper. Besides, the use of soybean hulls provided high volumetric productivities at shorter times, which may decrease production costs considering a scaled process.

Bassani Georgina

Papers

Potential use of soybean hulls and waste paper as supports in SSF for cellulase production by Aspergillus niger