Pigment producing soil bacteria of Sundarban Mangrove Forest

摘要

Sundarban Mangrove Forest (SMF) is a tidal forest of Bangladesh and ecologically unique ecosystemfor natural resource. SMF soils were studied for pigment producing bacteria. The pH of the collectedmangrove soil samples ranged 6.02 - 7.70. The bacterial load varied from 2.68 × 107 to 3.38 × 107 cfu/g soilwith an average bacterial count of 2.90 × 107 cfu/g. The highest bacterial count of 3.38 × 107 cfu/g wasobserved in the soil of Katka, and the lowest count of 2.68 × 107 cfu/g was noticed at Tambulbunia. Theselected isolates were cultured in different pigment producing media for pigment production and LB mediumsupplemented with 5% sucrose showed the best response towards maximum pigment production. Thephysico-chemical analyses revealed that pH 6.5, temperature 37°C and salt concentration of 2 - 14% wereoptimum both for bacterial growth and pigment production. Thirty pigment producing bacterial isolates wererandomly selected for detail study. Most of the isolates belong to the genus Bacillus including B. subtilis (8),B. firmus (4), B. pumilus (3), B. licheniformis (2), B. pantothenicus (2), B. lentus (2), B. acidocaldarius (1),B. schlegelii (1), B. azotoformans (1), B. polymixa (1), B. stearophilus (1), B. alcalophilus (1), B. fastidiosus(1), B. lentimorbus (1). Only one isolate was Planococcus halophilus. Eight best pigment producing bacterialisolates were further confirmed through 16S rDNA sequence analysis. Different types of color such asyellow, orange, cream, brown color pigment producing bacteria were observed in the soil sample.