摘要
β-mannanase is an enzyme that is commonly expressed in environmental bacteria. It degrades hemicellulose found in plant material and recycles nutrients back into the environment. Because this enzyme significantly contributes to biodegradation and has recently been applied in industry, we conducted a comparative analysis of bacterial isolates found in soil samples from Schirmacher Oasis, Antarctica, and Sabah, Malaysia that were capable of degrading mannan. A total of 9 bacterial isolates from Antarctica and 30 bacterial isolates from Malaysia exhibited β-mannanase activity. These bacteria were differentiated and clustered using their random amplified polymorphic DNA （RAPD） profiles, and the β-mannanase activity of these isolates was tested at different temperatures and pH. Five out of 9 Antarctica isolates and seven out of 30 Malaysian isolates were identified based on their 16S rDNA sequences. Identified bacterial isolates from Antarctica were： MP1 （Bacillus amyloliquefaciens）, MP2 （Bacillus pumilus）, MP5 （Bacilluspumilus）, A40 （Arthrobacter sp.）, and C27 （Arthrobacter oxydans）. Identified bacterial isolates from Ma- laysia were： Y1 （Paenibacillus sp.）, Y2 （Bacillus sp.）, Y16 （Paenibacillus sp.）, Y18 （Paenibacillus sp.）, A7 （Paenibacillus sp.）, B26 （Streptomyces sp.）, and D4 （Paenibacillus amylolyticus）. β-mannanases produced by the Antarctica bacterial isolates MP1 （Bacillus amyloliquefaciens） and A40 （Arthrobacter sp.） were active at 5℃ and 20℃, respectively, while the β-mannanase pro- duced by the bacterial isolate from Malaysia, A7 （Paenibacillus sp.）, was active at 35 ℃.
β-mannanase is an enzyme that is commonly expressed in environmental bacteria. It degrades hemicellulose found in plant material and recycles nutrients back into the environment. Because this enzyme significantly contributes to biodegradation and has recently been applied in industry, we conducted a comparative analysis of bacterial isolates found in soil samples from Schirmacher Oasis, Antarctica, and Sabah, Malaysia that were capable of degrading mannan. A total of 9 bacterial isolates from Antarctica and 30 bacterial isolates from Malaysia exhibited β-mannanase activity. These bacteria were differentiated and clustered using their random amplified polymorphic DNA （RAPD） profiles, and the β-mannanase activity of these isolates was tested at different temperatures and pH. Five out of 9 Antarctica isolates and seven out of 30 Malaysian isolates were identified based on their 16S rDNA sequences. Identified bacterial isolates from Antarctica were： MP1 （Bacillus amyloliquefaciens）, MP2 （Bacillus pumilus）, MP5 （Bacilluspumilus）, A40 （Arthrobacter sp.）, and C27 （Arthrobacter oxydans）. Identified bacterial isolates from Ma- laysia were： Y1 （Paenibacillus sp.）, Y2 （Bacillus sp.）, Y16 （Paenibacillus sp.）, Y18 （Paenibacillus sp.）, A7 （Paenibacillus sp.）, B26 （Streptomyces sp.）, and D4 （Paenibacillus amylolyticus）. β-mannanases produced by the Antarctica bacterial isolates MP1 （Bacillus amyloliquefaciens） and A40 （Arthrobacter sp.） were active at 5℃ and 20℃, respectively, while the β-mannanase pro- duced by the bacterial isolate from Malaysia, A7 （Paenibacillus sp.）, was active at 35 ℃.
基金
the Malaysian Antarctic Re-search Program (MARP)
the Academy of Sciences Malaysia for funding this research project(Grant no.95500-66)
