Kumar Shristi, Hatha A A M, Christi K S
Department of Biology, School of Pure and Applied Sciences, The University of the South Pacific, P.O. Box, 1168, Suva, Fiji Islands.
Rev Biol Trop. 2007 Sep-Dec;55(3-4):777-86. doi: 10.15517/rbt.v55i3-4.5954.
The diversity and load of heterotrophic bacteria and fungi associated with the mangrove soil from Suva, Fiji Islands, was determined by using the plate count method. The ability of the bacterial isolates to produce various hydrolytic enzymes such as amylase, gelatinase and lipase were determined using the plate assay. The heterotrophic bacterial load was considerably higher than the fungal load. There was a predominance of the gram positive genus, Bacillus. Other genera encountered included Staphylococcus, Micrococcus, Listeria and Vibrio. Their effectiveness on the degradation of commercial polythene carry bags made of high density polyethylene (HDPE) and low density polyethylene (LDPE) was studied over a period of eight weeks in the laboratory. Biodegradation was measured in terms of mean weight loss, which was nearly 5 % after a period of eight weeks. There was a significant increase in the bacterial load of the soil attached to class 2 (HDPE) polythene. After eight weeks of submergence in mangrove soil, soil attached to class 1 and class 3 polythene mostly had Bacillus (Staphylococcus predominated in class 2 polythene). While most of the isolates were capable of producing hydrolytic enzymes such as amylase and gelatinase, lipolytic activity was low. Class 2 HDPE suffered the greatest biodegradation.
采用平板计数法测定了与斐济群岛苏瓦红树林土壤相关的异养细菌和真菌的多样性及数量。通过平板试验测定了细菌分离株产生淀粉酶、明胶酶和脂肪酶等各种水解酶的能力。异养细菌数量显著高于真菌数量。革兰氏阳性菌属芽孢杆菌占优势。其他菌属包括葡萄球菌、微球菌、李斯特菌和弧菌。在实验室中对它们在八周时间内对由高密度聚乙烯（HDPE）和低密度聚乙烯（LDPE）制成的商用聚乙烯塑料袋的降解效果进行了研究。通过平均重量损失来衡量生物降解情况，八周后平均重量损失近5%。附着在2类（HDPE）聚乙烯上的土壤中细菌数量显著增加。在红树林土壤中浸泡八周后，附着在1类和3类聚乙烯上的土壤中大多是芽孢杆菌（2类聚乙烯上以葡萄球菌为主）。虽然大多数分离株能够产生淀粉酶和明胶酶等水解酶，但脂肪分解活性较低。2类HDPE的生物降解程度最大。
