Isolasi dan Identifikasi Mikrob Tanah Pendegradasi Selulosa dan Pektin dari Rhizosfer Aquilaria malaccensis

Abstract

Gaharu (agarwood) is one of non-timber forest product that has been used for thousand years by ancestors in religious rituals, as perfume, incense, fragrance, even for medicines. Gaharu can be found commonly from trees of genus Aquilaria. Scientists indicated various hypothesis to understand agarwood formation in the tree, one of them is pathological hypothesis. In pathological hypothesis, agarwood formation is caused by microbial infection inside plant tissue host. The presence of pathogen attack will make the host to produce phytoalexins as self defence. Thus, it is estimated that agarwood formation conducted by accumulation of phytoalexins in damage plant tissues. This research aims to explore soil microbes in rhizosphere of Aquilaria malaccensis which have ability to degrade cellulose and pectin. Screening was conducted to observe cellulase and pectinase activities. Isolates were screened in selective media, namely CMC (carboxymethyl cellulose), CPAF (citrus pectin agar for fungi) and CPAB (citrus pectin agar for bacteria). Cellulase and pectinase activity was specifically shown by clear zone around the cultures after flooding treatment with stain solution. Identification was conducted for isolate that showed the highest solubilizing index after screening section. Soil parameters that play role in microbial living in nature had been measured, such as pH, soil moisture content, bulk density, Ca, Mg, Fe, Cu, Mn, Zn, C-organic, total Nitrogen, and available Phosphate. In this research, 26 isolates of fungi and 29 isolates of bacteria were isolated. It was found that seven isolates of fungi and six isolates of bacteria showed positive result with clear zone around the cultures. The results of identification showed soil microbes with the highest cellulose and pectin solubilizing index are Bacillus brevis for bacteria and genus Helicoma for fungi.