BANGLADESH JOURNAL OF BIOCHEMISTRY

Bangladesh Journal of  Biochemistry
AN INTERNATIONAL JOURNAL IN BIOCHEMICAL SCIENCE

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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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