Martin N, Guez M A U, Sette L D, Da Silva R, Gomes E
UNESP - Universidade Estadual Paulista, Laboratório de Bioquímica e Microbiologia Aplicada-IBILCE, São José do Rio Preto/SP, Brazil.
Mikrobiologiia. 2010 May-Jun;79(3):321-8.
Thermophilic organisms produce thermostable enzymes, which have a number of applications, justifying the interest in the isolation of new thermophilic strains and study of their enzymes. Thirty-four thermophilic and thermotolerant fungal strains were isolated from soil, organic compost, and an industrial waste pile based on their ability to grow at 45 degrees C and in a liquid medium containing pectin as the only carbon source. Among these fungi, 50% were identified at the genus level as Thermomyces, Aspergillus, Monascus, Chaetomium, Neosartoria, Scopulariopsis, and Thermomucor. All isolated strains produced pectinase during solid-state fermentation (SSF). The highest polygalacturonase (PG) activity was obtained in the culture medium of thermophilic strain N31 identified as Thermomucor indicae-seudaticae. Under SSF conditions on media containing a mixture of wheat bran and orange bagasse (1:1) at 70% of initial moisture, this fungus produced the maximum of 120 U/ml of exo-PG, while in submerged fermentation (SmF) it produced 13.6 U/ml. The crude PG from SmF was more thermostable than that from SSF and exhibited higher stability in acidic pH.
嗜热生物产生耐热酶，这些酶有许多应用，这使得人们对分离新的嗜热菌株及其酶的研究产生了兴趣。基于它们在45℃以及在以果胶作为唯一碳源的液体培养基中生长的能力，从土壤、有机堆肥和工业废料堆中分离出了34株嗜热和耐热真菌菌株。在这些真菌中，50%在属水平上被鉴定为嗜热栖热菌属、曲霉属、红曲霉属、毛壳菌属、新萨托菌属、帚霉属和嗜热毛霉属。所有分离菌株在固态发酵（SSF）过程中都产生果胶酶。在被鉴定为印度嗜热栖热假丝酵母的嗜热菌株N31的培养基中获得了最高的聚半乳糖醛酸酶（PG）活性。在初始水分含量为70%、含有麦麸和橙渣混合物（1:1）的培养基上进行固态发酵条件下，这种真菌产生的胞外PG最高可达120 U/ml，而在深层发酵（SmF）中它产生13.6 U/ml。深层发酵得到的粗PG比固态发酵得到的更耐热，并且在酸性pH下表现出更高的稳定性。
