MATERIALS AND METHODS
Isolation of cellulose degrading bacteria (CDB) by enrichment
method
Top soil samples (0 to 10 cm) were collected from the tea farm of
UPASI Tea Research Institute using auger. The soil samples were air
dried under shade and sieved through a 2.0 mm width mesh to remove
stones and plant debris. Cellulose degrading bacteria (CDB) were
isolated by enrichment method. Soil samples (10.0 g) obtained from a
tea field were added in minerals salts medium broth containing 0.1% of
carboxyl methyl cellulose and incubated at 30°C and 100 rpm for two
days of incubation under the shaking condition. From this stock, 10 ml
of the sample was taken and transferred to fresh MSM broth containing
0.1% CMC substrate as carbon source. After overnight incubation at
30°C, a 10 ml portion of supernatant fluid were serially diluted up to 107,
and then the 103, 104 and 105 dilutions were plated into the mineral salt
medium (100 ml) with CMC (0.1%) as carbon source. Plates were
incubated at 30°C and examined periodically for colonies which showed
areas of clearing. Representative colonies were transferred to nutrient
broth, allowed to grow for 24 h, diluted and plated again on cellulose
agar. This procedure was repeated until a pure culture of the cellulolytic
bacterium was obtained. The cellulolytic isolate was maintained at 4°C
on cellulose agar. Spread plate technique was followed and colonies
which appeared on CMC were amended on MSM media. Again, they
were streaked on mineral salts medium with 0.1% cellulose media in
order to bring pure cultures of CDB.