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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.
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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.
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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.
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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.
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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.
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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.
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