Biodiversity and biochemical characterization of bacteria from terrestrial subsurface environment

Abstract

Forty-one aerotolerant subsurface bacterial colonies were isolated from terrestrial subsurface environment at various depth from 5 feet to 50 feet at 5 feet intervals. Out of 41 colonies, 32 morphologically distinct bacterial colonies were selected for gram staining reaction, various sugar utilization pattern and scanning electron microscopic studies. Most of the bacterial colonies were gram-positive rods; some are gram-negative rods, gram-positive cocci and coccobacilli, and gram-negative coccobacilli respectively. Seven bacterial colonies NTN33, NTN34, NTN35, NTN36, NTN01, NTN02 and NTN03 isolated from 40 to 50 feet depth were neither gram positive nor gram negative, and no distinct morphological shape but gigantic structure have identified in that bacteria. The bacterial size were identified on the bacteria NTN36, NTN35, NTN01, NTN30, NTN34, NTN02 as 4.5 µm, 4.1 µm, 3.5 µm, 3.4 µm, 3.2 µm and 2.2 µm. Gigantic rod surrounded by capsular sheath and gigantic rod with footprint like appearance were identified in the bacteria NTN02 and NTN36; those are isolated from 45 and 50 feet depth. Intracellular granules were also found in bacteria NTN34, NTN35 and NTN01. In total, 24 different sugars had used to analyse the sugar utilization pattern of that 32 bacteria. Most of the bacteria have utilized only 03 different types of sugars either maltose, galactose and glycerol or lactose, trehalose and mannose. However, the bacteria NTN16, NTN12, NTN06, NTN24, NTN27, NTN28, NTN34 and NTN02 had utilized 14 different sugars. Nevertheless, very few bacteria have utilized the l-arabinose, α-methyl-d-gluconate and inulin. None of the bacteria had utilized the sugar sodium gluconate, salicin, glucosamine and dulcitol.