Potensi Bacillus sp. Galur G3, Bacillus firmus E65, dan bakteri metanotrof sebagai penghambat pertumbuhan patogen Xanthomonas oryzae pv. oryzae dan Rhizoctonia solani

Abstract

The use of bacilli and methanotropic bacteria as biocontrol agents for rice bacterial pathogens of X. oryzae pv. oryzae and R. solani can enhance rice production and reduce methane emission from rice fields. Some of methanotrophs had nitrogen fixation activity. Antagonism methods was tested to determine the ability of two bacilli species (Bacillus sp. G3 and B. firmus E65) and two methanotrophs (BGM 9 and SKM 14) in inhibiting growth of X. oryzae pv. oryzae and R. solani and inhibition between the two groups of bacteria. Methanotrophs (BGM 9 and SKM 14) inhibited growth of X. oryzae pv. oryzae with inhibition index (IP) of 2,27 and 2,79 respectively. Bacillus sp. G3, B. firmus E65 and SKM 14 isolates inhibited growth of R. solani with inhibition index of 0.63, 0.64, and 0.56 respectively. B. firmus E65 inhibited growth of methanotrophs (BGM 9 and SKM 14) and R. solani. Formulation of biocontrol agents containing Bacillus sp. G3 and methanotrophs (BGM 9 and SKM 14) can be done because there was no antagonism among the three bacteria. However the combination of B. firmus E65 and the metanotrophs should not be done in one formulation because of the antagonism between B. firmus E65 and the metanotrophs.