Abstract

VANEGAS-ZAMORA, Rubell Juneidy; MENDEZ-ARTEAGA, Jonh Jairo  and  MURILLO-ARANGO, Walter. Amylolytic potential of microorganisms associated to rice crops cultured on starch from rice byproducts. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2015, vol.39, n.153, pp.514-519. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.271.

We evaluated the amylolytic potential of microorganisms isolated from substrates related to rice crops cultured on starch extracted by the alkaline method from third category Índica and Fedearroz 60 rice varieties. The starch was subjected to direct fermentation with microorganisms isolated from the substrates; we evaluated the effect of the type of microorganism and the fermentation time (24, 48 and 72 h) in 50 ml reactors supplemented with 20 g/l of starch, and we measured total sugars, reducing sugars and direct amylolytic activity. Among the microorganisms recovered from the substrates, Aspergillus spp., Rhizopus oryzae, Penicillium spp. and Candida krusei were especially efficient given their growth rate in the starch-supplemented medium, and their differential amylolytic activity. The most efficient organism was Aspergillus spp., releasing 2.85 g/l of reducing sugar at 72 h in starch from the Fedearroz 60 rice variety, and the least efficient was C. krusei, with 0.300 g/l of reducing sugars during the same fermentation time, apparently regardless of the variety. This Índicates a significant amylolytic potential of native microorganisms associated with rice crops and their significant effect on the structure and chemical composition of the starch varieties under study.

Keywords : Rice starch; agroindustrial byproducts; amylolytic potencial; native microorganism.

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