Vertical structure of bacterial communities in peats of the Yakhroma river floodplain
The abundance and taxonomic structure of soil bacterial communities have been studied in different geomorphological parts of the Yakhroma floodplain. It has been found that the numbers of bacteria reach a peak in calcareous peat soil under forest near the floodplain terrace, decreasing to a minimum in soddy alluvial soil near the riverbed. All soils are characterized by the presence of different ecological-trophic bacterial groups capable of peat destruction. Seasonal dynamics of the structure of bacterial communities and, in some soil types, its spatial dynamics accounted for by changes in the botanical structure of peat across its profile have been revealed. All peat soils in the floodplain have high contents of organic matter and neutral pH and, therefore, are favorable biotopes for the development of saprotrophic bacteria. This, in turn, largely accounts for high productivity and stability of this agroecosystem as a whole.
PEATLAND BACTERIA AS ALTERNATIVE SOURCES FOR CELLULASE (BAKTERI GAMBUT SEBAGAI SUMBER ALTERNATIF SELULASE)
Riset ini dilakukan untuk mengisolasi dan mengidentifikasi bakteri dari tanah gambut Kota Pontianak, Kalimantan Barat. Sebanyak 9 dari 18 isolat bakteri diketahui memiliki aktivitas selulolitik. Isolat aktif tersebut menunjukkan terbentuknya zona hidrolisis di sekitar koloni bakteri ketika ditumbuhkan pada media mengandung karboksimetil selulosa 1%. Tiga isolat yaitu Yersinia pseudotuberculosis RAG21, Yersinia pseudotuberculosis RAG25, dan Proteus penneri RAG31 menunjukkan rasio diameter zona hidrolisis terhadap koloni, dengan rasio sebesar 2,73±0,15, 2,61±0,15, dan 4,14±0,30 secara berturut-turut. Kata Kunci: bakteri gambut, humat, selulase, Yersinia pseudotuberculosis , Proteus penneri
Bacteria of the hydrolytic complex in hydromorphic forest soils.
For the first time, the rapid multipoint method was used to characterize the complex of hydrolytic bacteria in hydromorphic forest soils. The soddy-gley soil differs markedly from the other hydromorphic soils by maximum values of the number and the diversity of hydrolytic bacteria. In the peaty-podzolic and peat soils, the only representative of bacteria capable of decomposing plant and microbial remnants is Bacillus, with the dominant species being Bacillus circulans. Spatial (along the soil profile) and temporal (spring-autumn) changes in the taxonomic structure of soil bacterial communities are revealed.