publicado na web em 13/06/2017 Lignin is present in plant cell secondary wall, associated to carbohydrates preventing their efficient hydrolysis, and cellulose pulp manufacture basically consists in breaking down the middle lamella of plant cells, individualizing fibers such as cellulose from the other biopolymers. Different levels of lignocellulose are found in plant residues and they can be decomposed by extracellular fungal lignin modifying enzymes, used as a tool to reduce waste materials in contaminated soils and effluents. In the paper mill industries, for instance, they are a suitable or complementary alternative to the traditional methods of pulping/bleaching, contributing to improve paper strength as well as to reduce the pitch content, the quantity of chemicals and the consume of electrical energy. The aim of this review was to describe the fungal degradation of lignocellulosic like-material, the non-specific enzymatic aspects of the attack of wood and agricultural wastes, the fungal ability for biosorption and bioconversion, and its applications in the pulp/paper industry and bioremediation.
Biosurfactants possess diverse chemical properties and provide important characteristics to the producing microorganisms, which can act as surface-actives and emulsifiers of hydrocarbon and others water insoluble substances. Most of them are lipopeptides synthetized by Bacillus. This study evaluated the biosurfactant production by strains of Bacillus previously obtained from liquid residues of sugar-alcohol industry. The bacterial isolates LBPMA: BSC, BSD, J1, J2 and L1 were cultivated in medium that induces production of biosurfactants (Landy medium). During 48 h of incubation, at intervals of 12 h, the total contents of proteins, reducing carbohydrates and surfactant activity of the filtrated growth media free of cells were evaluated. The results showed that these strains use glucose as a source of carbon, energy and for synthesis of surfactant. In this medium (24 h), the best producer of biosurfactant was the strain LBPMA-J2, molecularly identified HIGHLIGHTS • Interest in biosurfactants has increased in the last two decades. • Surfactin from Bacillus is one of the most effective biosurfactants. • Bacillus species are known as the main producers of extracellular enzymes. • Isolation of new strains is strategic for several fields of biotechnology. Santos, E.C.L.; et al.
Shrimps fishing, especially the pink (Farfantepenaeus brasiliensis and F. subtilis) and the white (Litopenaeus schmitti) ones, are relevant for the Brazilian Northeast economy, and their price depends on their aspect-quality. They are rich in lipids/proteins, which are a target for autolytic and microbial enzymes. These may not change the shrimps' appearance but generate substances that may cause poisoning, as histamines. This work compared the microbial quality of fillets and shells of these three shrimps, harvested in two years, after cooking and storage under different freezing times (0-90 days), as well as the total carotenoids (TC) and antioxidant activity (AA%) of ethanolic extracts from all the samples, using spectrophotometry and DPPH test. None histaminogenic and few mesophilic bacteria were isolated (all Gram+ species of Corynebacterium, Listeria, Arthrobacter, Bacillus and Erysipelothrix), but in lower number than the tolerability limit. The TC and AA% of fresh shells from time "zero" were always higher than those of fillets, mainly for F. subtilis. Cooking increased TC and AA% of fillets, but reduced them in shells, and both parameters declined along the freezing. Thin-layer chromatography and spectrophotometric scanning of all the extracts and standards evidenced astaxanthin as the main carotenoid.
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