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PRODUCTION
OF CELLULOSE-DEGRADING ENZYMES FROM A NEWLY ISOLATED THERMOPHILIC
FUNGUS THERMOASCUS AURANTIACUS
IN SHAKE-FLASK AND IN BIOREACTOR CULTURES
Donald James GOMES,1*
and Walter STEINER2
1Department of
Microbiology, University of Dhaka, Dhaka-1000, Bangladesh and
2Institute of Biotechnology, Technical University Graz, Petersgasse
12, A-8010, Graz, Austria
_______________________________________________________________________
*To whom correspondence should be addressed
Abstract
The production
of cellulases was investigated with a newly isolated strain of thermophilic
fungus, Thermoascus aurantiacus. The medium composition was optimized
on a shake-flask scale using the Graeco-Latin square technique. The
traditional one-factor-at-a-time method was employed for selecting
the effective factors and the initial test range of each ingredient.
The optimized medium composition was found to be 3.5% steam-treated
ground wheat straw, 1.0% pharmamedia (cotton seed-derived protein),
0.5% KH2PO4 and 0.1% Tween 80. The enzyme production in shake-flask
cultures using the optimized culture medium with an initial pH range
of 4.0-5.5 were maximum when incubated at 45-50 C under shaking at
150 rpm. The optimized culture medium and culture conditions gave
3.6 nkat of filter paper cellulase (FPCase), 155.8 nkat of carboxymethyl
cellulase (CMCase) and 40.8 nkat of -glucosidase per ml of culture
filtrate at 240 h of shake culture. In bioreactor cultures using the
optimized culture medium, the fungus produced maximum levels of the
enzymes when pH was not controlled and starch-glucose-grown preculture
was used as inoculum. Batch cultivation under these conditions allowed
the production of 3.7 nkat of FPCase, 119.7 nkat of CMCase and 48.3
nkat of -glucosidase per ml of culture filtrate in 158 h.
Key words: Cellulase,
Optimization, Thermoascus aurantiacus, Wheat straw
PURIFICATION, SUBUNIT STRUCTURE AND SOME CHARACTERISTICS OF THREE
SILKWORM PUPAE PROTEINS FROM BOMBYX MORI L
Md. Razaul Karim, M. Habibur Rahman , Parvez Hassan 1 , Nurul Absar*.
*Department of Biochemistry, Rajshahi University, Rajshahi -6205,
Bangladesh
(Received for publication, 25 November 1998; and in revised form,
31 August 2000)
Key Words: Silkworm, (Bombyx mori L.), Pupae protein, Relative molecular
mass, Subunit structure, Pup=Pupae protein
Abstract
Three major proteins, designated as Pup-1, Pup-4 and Pup-6 were purified
from crude protein extract of silkworm (Bombyx mori L.) pupae by gel
filtration on Sephadex G-75 followed by ion exchange chromatography
on DEAE-cellulose to a homogenous state as confirmed by polyacrylamide
disc gel electrophoresis (PAGE). SDS-polyacrylamide gel electrophoresis
of Pup-1 protein fraction showed a single band with molecular weight
of 190 kDa in presence or absence of -mercaptoethanol indicating that
the Pup-1 protein is a single polypeptide chain. The protein Pup-4
gave 4 bands with relative molecular masses of about 80 kDa , 48 kDa,
31 kDa and 14 kDa in absence of -mercaptoethanol on SDS-PAGE, suggesting
that the tertameric subunits of Pup-4 protein are held together by
non-ionic hydrophobic interactions. On the other hand, the protein
Pup-6 gave a single band (145 kDa) in absence of -mercaptoethanol
on SDS-PAGE while in the presence of -mercaptoethanol, Pup-6 protein
dissociated into 4 subunits with relative molecular masses of 53 kDa,
43 kDa, 33 kDa and 15 kDa. This suggested that the 4 subunits of Pup-6
protein are held together by disulfide bonds. Further, the relative
molecular masses of the purified native proteins were estimated to
be 185 kDa, 170 kDa and 140 kDa for Pup-1, Pup-4 and Pup-6, respectively
by the gel filtration method and are in good agreement with that obtained
by polyacrylamide gel electrophoresis. Pup-1, Pup-4 and Pup-6 proteins
were judged to be glycoproteins having sugar content of 4.05%, 3.15%
and 0.605% respectively. The major amino acid compositions of pupae
proteins were determined.
Corresponding author: M. Habibur Rahman Department of Biochemistry,
Rajshahi
University, Rajshahi -6205, Bangladesh
1 Present address: Institute of Biological Sciences, Rajshahi University,
Rajshahi- 6205.
ANTINEOPLASTIC ACTIVITY OF CHLOROACETOHYDROXAMIC ACID IN COMBINATION
WITH ULTRASOUND
J.A. Khanam,
Department of Biochemistry,
Rajshahi University,
Rajshahi-6205,
Bangladesh
Abstract
Antitumour activity of chloroacetohydroxamic acid (CHA), ultrasound
and CHA in combination with ultrasound has been studied against Ehrlich
ascites carcinoma (EAC) cells in Swiss A mice. It has been found that
individual treatment of both CHA and ultrasound has enhanced the longivity
of tumour bearing mice. The logivity has increased remarkably with
the combination treatment. Further in comparison with individual treatments
(CHA and ultrasound) this combination treatment has restored the altered
haematological parameters and alkaline phosphatase (ALKP) activity
more closely towards normal.
IN VITRO STUDY OF THE EFFECT OF INDAN-1-ACIDS ON THE OXIDATION OF
INDOLE-3-ACETIC ACID BY HORSERADISH PEROXIDASE ENZYME
Sitesh Chandra Bachar* and Samir Chandra Lahiri
Department of Pharmaceutical Technology, Medicinal Chemistry Division,
Jadavpur University, Calcutta 700032, India
(Received for publication, 22 December 1999; and in revised form,
15 November 2000)
Key words: Indan-1-carboxylic acid, Indan-1-acetic acid, Indole-3-acetic
acid, Horseradish peroxidase.
Abstract
The effect of two synthetic auxins, indan-1-carboxylic acid and indan-1-acetic
acid, on the peroxidase-catalyzed oxidation of a natural auxin, indole-3-acetic
acid (IAA), was studied at different time intervals. Both the indan-1-acids
appeared to inhibit oxidation of IAA by the enzyme horseradish peroxidase.
After 30 minutes of in vitro exposure to the peroxidase, IAA was completely
oxidised while in the presence of indan-1-carboxylic acid and indan-1-acetic
acid, the oxidation of IAA decreased to 84.45% and 89.40% respectively.
Of the two acids tested, indan-1-carboxylic acid showed a comparatively
higher efficacy in controlling oxidative degradation of IAA than indan-1-acetic
acid.
* Author to whom all correspondence should be addressed: Sitesh C.
Bachar, Department of Pharmacy, University of Dhaka, Dhaka 1000, Bangladesh.
E-mail : scbachar@yahoo.com
ANTITUMOR ACTIVITY OF VITIS TRIFOLIA LINN. (FAMILY-VITACEAE)
Joydeb K. KUNDU1*, Abu Shara S. ROUF1, Md. Nazmul HOSSAIN1 and Md
Aftab UDDIN2
1Department of Pharmacy, University of Dhaka, Dhaka-1000, Bangladesh
2Department of Biochemistry, University of Dhaka, Dhaka-1000, Bangladesh
(Received 05 March 2000, revised 18 January 2001)
Abstract
Sun-dried whole Vitis trifolia L. plant powder was extracted with
n-hexane and the extract evaporated to dryness. The residue was subjected
to vacuum liquid chromatography (VLC) using petroleum ether and ethylacetate.
Four VLC fractions namely H1, H2, H3 and H4 as well as a partially
purified fraction VT-1 (obtained by rechromatography of fraction H4)
were studied by potato disc bioassay method for antitumor activity.
Significant inhibitions of crown gall tumor formation were observed
for fractions H2, H3, H4 and VT-1 while fraction H1 showed no significant
inhibition.
Keywords: Vitis trifolia, Agrobacterium tumefaciens, Crown gall tumor,
Potato-disc bioassay
*Corresponding author
Department of Pharmacy
University of Dhaka, Dhaka-1000, Bangladesh
Ph: 880-2-9661900-59 Extn. 4835
Fax : 880-2-8615583
Email : kundujk@yahoo.com
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