Four sites i n one ot the ho t.. springs ot Shalla werernselec ted for the study. The wate r fr om t he sites me rge to formrna s t ream whic h forms a te mperature gradient . In this study f ourrnmedia we r e compa1;' ed tOI? the c ultivation and i solation o frnaerobic heter otrophic bac ter i a. The pH of the ho t spring wasrn8. 7 with a temperature of 9G-56'C . The f o rmulated Illedia werernadjusted to pH values o f 7 .0-13 .0. Howeve r , hlgh count s ofrnbacte ria (lxlOl - 7x lOt c f u/ mll was only r egis tered when the pHrnwas ad juste d be twee n 8.0 and 9.0. A medi um containing normalrnconce ntra tion of Trypton Soya Agar (TSA) was effective i nrns uppo rt ing the growth of bacteria t han a med i um c on taining one quarternr strength of TSA o r supplement o f trace minerals.rnReplaci ng trac e minerals wi th hot s pri ng "" ate r improved therntotal numbe r of bacteria irowlng and also the number orrni so l ates.rnThcrmophl1ea were nume r o us (l:d Ol __ 1x l 0' clu/rol) thanrnthe rmo tol e r ants (2xlOl_2xl O( c fu/ml) at all sites . Thernpopulation of Bac illus brevis , Bac illus spbae ricu8, Bacillusrns t e arothermQphilu3 and Mi c r ococcus sp. was found to be low atrnl owe r e nvironmental temperatures than at hliher environmentalrntemperatures .rnIn t he course of t hi s s tudy a total of 44rnmicro organisms we r e isolated and char.cterlJ1ed. Twenty ninernwe r e identified to the s pecies level and were touftd to bernmembe r s o f genus Baci llus .rnThree isolates were Cram-positive cocci id e ntifiedrnt o the ge nus l eve l - Micrococcus. The r e main i ng 12 isolatesrnwere ei ther Gram-positi ve , filame ntous or no n- filamentous r od srnwh ich need a deta il ed bioc he mi c al analysis for i denlifi c ation .rnTo identify if any o f the isolates may havernindustrial applications , they we r e c hecked f o r product i on o frnamylase and protease . Fifteen o f the isolates producedrnprotease, 18 amylase and eleven I-roduced both amylase andrnprotease.