Extra-cellular chitinase production by a chitinolytic fungus Trichoderma harzianum TUBF 966 using submerged fermentation was studied. Colloidal chitin (1.5% w/v) was used as sole carbon source. Maximum chitinase production (14.7 U/ml) was obtained when fermentation was carried out at 30 degrees C for 96 h using 72 h old mycelium in a medium containing colloidal chitin 1.5% (w/v) as carbon source and 0.42 (% w/v) peptone as nitrogen source (pH 5.5). Supplementation of additional carbon sources (0.75% w/v) showed no further enhancement in chitinase production while supplementation of nitrogen sources (0.42% w/v) such as peptone and tryptone in the fermentation medium showed a marked increase in production. The process parameters that controlled chitinase production by the fungus were studied and presented here.
Solid-state fermentation was carried out for the production of alpha-amylase using Aspergillus oryzae. Different oil cakes such as coconut oil cake (COC) sesame oil cake (SOC), groundnut oil cake (GOC), palm kernel cake (PKC) and olive oil cake (OOC) were screened to be used as substrate for the enzyme production and also compared with wheat bran (WB). GOC was found to be the best producer of the enzyme among these. Combination of WB and GOC (1:1) resulted higher enzyme titres than the individual substrates. Maximum amount of enzyme (9196 U/gds) was obtained when SSF was carried out using WB + GOC, having initial moisture of 64% and supplemented with lactose and ammonium nitrate (1% each) at 30ºC for 72h using 2 mL spore suspension (6x10(7)spores/ml). Partial purification of the enzyme using ammonium sulphate fractionation resulted in 2.4-fold increase in the activity. The enzyme showed molecular weight of 68 KDa by SDS-PAGE. Except Mn, all other metal ions such as Ca, K, Na, Mg were found to be inhibitory for the enzyme activity. The enzyme was optimally active at 50(0)C and pH 5.0. Fermentação no Estado Sólido foi empregada na produção de alfa-amilase usando Aspergillus niger. Diferentes tipos de torta foram utilizadas, como torta de óleo de coco (COC), torta de de óleo de amendoim (GOC) torta de óleo de sesamo (SOC), torta de palma (PKC) e torta de óleo de oliva (OOC) foram selecionadas para serem usadas como substratos para produção de enzima e comparadas com o farelo de trigo (WB), GOC foi escolhido por ser o que produziu maiores concentrações de enzima. A combinação WB e GOC (1:1) resultou em maiores títulos da enzima quando em comparação com os substratos individuais. A máxima concentração de enzima (9196 U/ gms) foi obtida quando a FES foi conduzida utilizando WB + GOC, com umidade de 64% e suplementada com lactose e nitrato de amônia (1% cada) a 300C por 72 horas utilizando 2 mL de uma suspensão de esporo (6x107sporos/ml). A purificação parcial da enzima usando frações de sulfato de amônio resultou num aumento de 2-4 vezes o aumento da atividade. A enzima apresentou um peso molecular de 68 Kda pelo SDS_PAGE. Exceto Mn, todos os outros íons metálicos como Ca, K, Na, Mg são inibitórios na produção da enzima
Rice bran was used as the substrate for screening nine strains of Rhizopus sp. for neutral protease production by solid-state fermentation. The best producer, Rhizopus microsporus NRRL 3671, was used for optimizing the process parameters for enzyme production. Fermentation carried out with 44.44 % initial moisture content at a temperature of 30 C for 72 h was found to be the optimum for enzyme secretion by the fermenting organism. While most of the carbon supplements favored enzyme production, addition of casein resulted in a marginal increase in protease yield. Fermentation was then carried out under optimized conditions to obtain the crude extract of the enzyme, which was partially purified by precipitation and dialysis. A 3-fold increase in the enzyme purity was achieved in this manner. The enzyme was found to be a metalloprotease, being activated by Mn2+, with maximal activity at a temperature of 60 C and pH 7.0. Farelo de arroz foi utilizado como substrato para seleção de nove linhagens de Rhizopus sp. com vistas a produção de protease neutra. A linhagem que apresentou maior produtividade da enzima foi Rhizopus microsporus NRRL 3671, sendo utilizada na otimização dos parâmetros do processos e produção da enzima. As condições otimizadas para produção da enzima foram 44% de umidade inicial, temperatura de 30ºC e 72h de fermentação.A suplementação do farelo de arroz com uma fonte de carbono favoreceu a produção da enzima, porém a adição de caseína resultou em um aumento marginal do rendimento em protease. Condições otimizadas foram utilizadas para obtenção do extrato cru da enzima que foi parcialmente purificado por precipitação e diálise. A enzima purificada teve sua atividade incrementada 3 vezes. A enzima foi classificada como metalo-protease, sendo ativada pelo Mn2+ , sendo que sua atividade máxima foi obtida a temperatura de 60ºC e a pH 7.0
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