Fermentation and enzyme treatments for sorghum

Sorghum (Sorghum bicolor Moench) is the fifth most produced cereal worldwide. However, some varieties of this cereal contain antinutritional factors, such as tannins and phytate that may form stable complexes with proteins and minerals which decreases digestibility and nutritional value. The present study sought to diminish antinutritional tannins and phytate present in sorghum grains. Three different treatments were studied for that purpose, using enzymes tannase (945 U/Kg sorghum), phytase (2640 U/Kg sorghum) and Paecilomyces variotii (1.6 X 10(7) spores/mL); A) Tannase, phytase and Paecilomyces variotii, during 5 and 10 days; B) An innovative blend made of tanase and phytase for 5 days followed by a Pv increase for 5 more days; C) a third treatment where the reversed order of B was used starting with Pv for 5 days and then the blend of tannase and phytase for 5 more days. The results have shown that on average the three treatments were able to reduce total phenols and both hydrolysable and condensed tannins by 40.6, 38.92 and 58.00 %, respectively. Phytase increased the amount of available inorganic phosphorous, on the average by 78.3 %. The most promising results concerning tannins and phytate decreases were obtained by the enzymes combination of tannase and phytase. The three treatments have shown effective on diminishing tannin and phytate contents in sorghum flour which leads us to affirm that the proposed treatments can be used to increase the nutritive value of sorghum grains destined for either animal feeds or human nutrition.

Medium composition influence on Biotin and Riboflavin production by newly isolated Candida sp

Complex B vitamins as Biotin and Riboflavin are required by living organisms, not only for growth but also for metabolite production, and the feed market classifies them as growth promoters. Since Brazil will soon be one of the world's biggest animal protein producers, feed production is a large consumer of vitamins and micronutrients. The industry requires 10 mg riboflavin/0.2 mg biotin per kilogram of feed; a ratio of 40 ~ 50:1. Although few studies have been conducted specifically on riboflavin production using factorial design and surface response method as an optimization strategy, it is a common practice in biotechnology with many research reports available. However, there are no reports on the use of statistical design for biotin production. This study set out to evaluate medium composition influence on biotin and riboflavin production using a statistical design. There are no studies relating biotin and riboflavin production by Candida sp LEB 130. In this preliminary study to improve the simultaneous production of biotin and riboflavin, the maximum riboflavin/biotin ratio of 8.3 µg/mL was achieved with medium component concentrations of: sucrose 30 g/L, KH2PO4 2 g/L, MgSO4 1 g/L and ZnSO4 0.5mL/L.

Inoculum padronization for the production of cutinase by Fusarium oxysporum

Cutinase is a versatile enzyme showing several interesting properties for application in industrial processes. The widespread use of this enzyme depends on the development of an efficient and low-cost production system. One of the most important steps in a fermentation process is the standardization of the inoculum characteristics. In this study, the production of cutinase by Fusarium oxysporum showed a statistically significant relationship with both the inoculum size and the inoculum PDA pH. The greatest activities were 19.1 U/mL at PDA pH 7.0 and 22.72 U/mL using an aliquot of 12.72 x 10(7) spores/mL. The macroscopic characteristics of the colonies of Fusarium oxysporum changed according to the variation of the medium pH, with the best results recorded in those colonies presenting a cotton white aspect.

Cutinase é uma enzima versátil, que apresenta propriedades interessantes para aplicação em processos industriais. O uso desta enzima em larga escala depende do desenvolvimento de um sistema de produção eficiente e de baixo custo. Uma das etapas mais importantes em um processo de fermentação é a padronização do inóculo. Neste estudo, houve uma associação estatisticamente significativa entre a produção de cutinase por Fusarium oxysporum e tamanho do inóculo e pH do meio PDA. As maiores atividades de cutinase foram 19,1 U/mL em PDA com pH 7,0 e 22,72 U/mL empregando um inóculo de 12,72 x 10(7) esporos/mL. As características macroscópicas das colônias de Fusarium oxysporum mostraram alterações em função do pH do meio, com as maiores atividades sendo registradas em presença de colônias brancas com aspecto cotonoso.

A rapid screening method for cutinase producing microorganisms

Both cutinase and lipase belong to the esterase group of enzymes (EC 3.1.1.X), which are capable of catalyzing the hydrolysis of ester bonds. Cutinase catalyzes the hydrolysis of cutin, an insoluble biopolyester which is the structural component of plant cuticles. As cutinase is an efficient catalyst in watery or organic media, it is potentially appropriate for the detergent, food and cosmetic industries. The objective of this work was to isolate microorganisms from plants and perform a pre-selection of molds showing esterase producing ability. The selected strains were then submitted to fermentation in media containing cutin. The lipolytic and cutinolytic activities of the supernatant were determined in order to differentiate lipase producers from cutinase-producing strains. The mold strain selected as the best cutinase producer was identified as being Fusarium oxysporium.

A cutinase pertence, como as lípases, ao grupo das esterases (EC 3.1.1.X), que são enzimas capazes de catalisar reações de hidrólise de ligações do tipo éster. A cutinase catalisa a hidrólise da cutina, um biopoliéster insolúvel que constitui o componente estrutural da cutícula das plantas. Esta enzima tem se mostrado um eficiente catalisador tanto em solução aquosa quanto em meios orgânicos, sendo potencialmente apropriada para usos em indústria de detergentes, alimentos e cosméticos. O objetivo deste trabalho foi isolar fungos de diversas fontes e realizar uma pré-seleção destes, quanto à habilidade em produzir esterase. As linhagens fúngicas pré-selecionadas como produtoras de esterase foram inoculadas em meio de cultivo contendo cutina extraída de maçã. As atividades cutinolítica e lipolítica foram medidas no sobrenadante das culturas a fim de diferenciar os microrganismos produtores de lipase dos produtores de cutinase. Uma linhagem isolada mostrou a maior atividade cutinolítica após 12 dias de fermentação em um meio contendo 1% de cutina e foi identificada como sendo o Fusarium oxysporium.