Back
to Volume contents
Bangladesh Journal of Biochemistry, Vol. 2, No. 2, 61-65,December
1996
STUDIES
ON EXTRACELLULAR PROTEASE FROM BACILLUS THURINGIENSIS SY8
H. U. SHEKHAR , A.
SARKER and M. Anwar HOSSAIN
Department of Biochemistry, University of Dhaka, Dhaka-1000, Bangladesh.
(Received 6 June 1996)
Abstract
Bacillus thuringiensis
(B. t.) Sy8, a lepidopteran pest pathogen was found to produce
extracellular metallo-and serine-proteases. The maximum activity of
metalloprotease was found 0.09 unit/ml at 24h of growth in nutrient
broth and that of serine protease was 0.06 unit/ml at 48h of growth
in the same media. EDTA (5mM) inhibited 90% extra cellular protease
activity of 24h growth culture, whereas 4mM phenylmethyl sulfonyl
fluoride (PMSF) caused 92% inhibition after 48h of growth. The role
of different proteinacious substances on protease production revealed
that peptone served as the best substrate.
top
Bangladesh Journal of Biochemistry, Vol. 2, No. 2,
67-74,December
1996
SACCHARIFICATION OF LIGNOCELLULOSICS BY ENZYMATIC
HYDROLYSIS FOLLOWING PHYSICAL AND CHEMICAL PRETREATMENTS
Donald James GOMES, Joshep GOMES
and Walter STEINER
Institute of Biotechnology, Technical University Graz,
Petersgasse 12, A-8010, Graz, Austria
(Received 29 June 1996)
Abstract
The effect
of a variety of physical and chemical pretreatments on saccharification
of lignocellulosics was studied using Thermoascus aurantiacus enzyme
preparatuin. Native substrates were highly resistant to enzymatic
hydrolysis. The untreated wheat straw, barely husk and corn cobs were
saccharified to only about 14%, 3% and 12%, respectively. Pretreatments
of these materials with alkali and peracetic acid were found to be
the most effective of the pretreatments methods used and up to about
80-85% treatments were moderately effective in increasing the degree
of saccharification. Major hydrolytic products from the substrates
identified by HPLC included glucose, xylose and cellobiose. Monosugar
content alone in the hydrolysis comprised about 80-90% of the total
reducing sugars.
top
Bangladesh
Journal of Biochemistry, Vol. 2, No. 2, 75-80,
December 1996
ABUNDANCE OF
VIBRIO CHOLERAE NON 01 IN A FISH CULTURE FARM THAT USES SEWAGE GROWN DUCKWEED AS
FISH FEED
M. Shahidul KABIR,
S. I. KHAN
Department of Microbiology, University of Dhaka.
M. S. ISLAM,
International Center for Diarrhoeal Disease Research, Bangladesh. (ICDDR, B)
(Received
6 July 1996)
Abstract
A fish culture
farm that uses sewage-grown duckweeds as fish feed at Mirzapur, Tangail,
Bangladesh, has been studied for the abundance of Vibrio cholera non
01 in different aquatic components. Samples were collected once every
month from May 1994 to April 1995. A total of 175 samples representing
59 duckweeds, 60 water, 28 fish gills and 28 fish intestinal contents
were analyzed for isolation and identification of V. cholerae non
01 following standard procedures. Proportion of V. cholerae non 01
was highest in fish gills (53.6%) followed by fish intestinal content
(42.8%), water (26.7%) and duckweeds (22.0%). Prevalence of V. colerae
non 01 was higher (33.0%) in the fish culture environment than that
of duckweeds farming ecosystem. In spite of this abundance of V. cholerae
non 01, no disease manifestation in fish samples was observed during
this study.
top
Bangladesh
Journal of Biochemistry, Vol. 2, No. 2, 81-87,
December 1996
PRELIMINARY PHARMACOLOGICAL STUDIES OF REPENONE : A ROTENOID ISOLATED FROM BOERHAAVIA
REPENS
Muniruddin AHMED,
Suman SHAHPAR, Samir K. SADHU, Joydeb K. KUNDU
and Bidyut K. DATTA
Department of Pharmacy, University of Dhaka, Dhaka-1000, Bangladesh.
(Received
18 August 1996)
Abstract
Pharmacological
studies of repenone,
a rotenoid isolated from Boerhaavia repens, was carried out on Swiss
albino mice and Long Evans rats. Repenone decreased spontaneous motor
activity and exhibited nervous system depressant effect. The compound
was found to have significant analgesic activity and produced marked
diuretic action. Repenone demonstrated no significant changes in the
levels of SGOT, SGPT and SALP, with the exception of marked increase
in blood uric acid and BUN. Histopathology of liver, kidney and spleen
revealed no appreciable changes in the cellular structures.
top
Bangladesh
Journal of Biochemistry, Vol. 2, No. 2, 89-93, December
1996
XYLANASE PRODUCTION BY BACILLUS SP. AZ5 GROWN ON SUGARS AND
AGRICULTURAL RESIDUES
Saleh MAHMOOD
and Ajmila ISLAM
Department of Biochemistry, University of Dhaka, Dhaka-1000, Bangladesh.
(Received
25 March 1997)
Abstract
Bacillus
sp. AZ5 isolated from local soil produced xylan-degrading enzyme
extracellularly. The organism grew well in medium containing
xylan, glucose, fructose, sucrose, maltose, and starch. Lactose and
xylose were poor substances for growth. Xylanaseproduction was repressed
in media containing glucose, fructose, xylose, sucrose and lactose,
whereas it increased with xylan, starch and maltose. Agricultural
residue such as wheat bran, rice bran, paddy husk and saw dust could
be used for growth of the bacteria and xylanase production. Among
the agricultural residue tested, wheat bran showed good growth of
the Bacillus and the xylanase activity.
top
Bangladesh
Journal of Biochemistry, Vol. 2, No. 2, 95-101, December
1996
HIGH-PERFORMANCE
LIQUID CHROMATOGRAPHIC DETERMINATION OF DIOSBULBIN D AND 8-EPILDIOSBULBIN E
ACETATE IN DIOSCOREA BULBIFERA TUBERS
M. Aftab UDDIN, M. Nazmul HUDA
and N. Hoque KHAN
Department of Biochemistry,
University of Dhaka, Dhaka-1000. Bangladesh.
(Received 6 April,
1997)
Abstract
A
successful high-performance liquid chromatographic method for the
determination of diosbulbin D and 8-epidiosbulbin E acetate is described.
The method used exhaustive methanol extraction of tubers and the separation
was carried out on a reverse-phase column using a mobile phase composed
of 35% methanol in deionised distilled water. The detection of column
effluent was done with a UV detector at 208 nm. The separation of
diosbulbin D and 8-epidiosbulbin E acetate was achieved with high
purity within 6.45 min and 8.66 min respectively. The analytical data
of standard diosbulbin D and 8-epidiosbulbin E acetate showed that
the peak area and concentration were linearly related. This method
is highly sensitive and suitable for detection and concentration-indicating
assay.
|
