Muhammad Akond | Jahangirnagar University (original) (raw)

Papers by Muhammad Akond

Biological Nitrogen Fixation Associated with Rice Production, 1996

Five strains of Azospirillum brasilense, were isolated from the roots of rice plants cultivated i... more Five strains of Azospirillum brasilense, were isolated from the roots of rice plants cultivated in Savar, Dhaka. Effects of temperature, pH, NaC1 and Zn on the nitrogen-fixing potential of the strains in batch culture were studied. The organisms preferred temperatures between 33 and 35°C, and a pH value of 7.0 for maximum nitrogen fixation. The amount of nitrogen fixed by the strains at optimum temperature and pH after 72 h ranged from 448 to 658 µg N/25 ml culture. All of the strains showed a gradual decrease in their nitrogen-fixing potential with increasing concentrations of NaCl and Zn.

Bangladesh Journal of Microbiology, 1970

The study of important nitrogen-fixing bacteria is very essential with a view to finding efficien... more The study of important nitrogen-fixing bacteria is very essential with a view to finding efficient strains to develop biofertilizer for crops like wheat. Biological nitrogen fixation is important in nonleguminous crop, e.g., rice and wheat farming systems because it is an inexpensive source of nitrogen for higher yields. This process diminishes the need for expensive chemical fertilizers, which have been associated with numerous health and environmental problems. Biological nitrogen fixation in agriculture usually refers to nodule forming dicotyledonous leguminous plants. Monocotyledonous plants like rice and wheat lacking genes for nodulation must depend upon nitrogen from chemical fertilizers and various sources of biological nitrogen fixation in the ecosystem by free-living or associative organisms. Azotobacter is a free-living nitrogen-fixing soil bacterium. This organism was first isolated and described by Beijerinck in 1901 1. Besides nitrogen fixation, Azotobacter has been found to synthesize growth promoting substances and antibiotics 2. By virtue of these attributes, Azotobacter can play nutritional and stimulatory roles and can benefit the plants with its manifold actions. Further, Azotobacter inoculation has been found to increase the growth and yield of a wide variety of cereals, pulses, vegetable crops, fruit crops and cash crops 3. It is indeed interesting to note that Azotobacter is among the first organisms to develop in a newly formed soil, and the number of this organism in soil runs parallel with its fertility 4. Though the occurrence and distribution of Azotobacter in the soils of different parts of the world have been well studied 5 , such occurrence and distribution in the soils of Bangladesh have so far received very little attention 6. The present work therefore

International Journal of Food Microbiology, Mar 1, 2009

A total of 225 carbonated soft drink (CSD) samples from nine brands, from various locations in fi... more A total of 225 carbonated soft drink (CSD) samples from nine brands, from various locations in five metropolitan cities of Bangladesh were examined to determine their bacteriological quality. Most samples were not in compliance with microbiological standards set by organizations like the World Health Organization (WHO). Pseudomonas aeruginosa was the predominant species with an incidence of 95%. Streptococcus spp. and Bacillus stearothermophilus were the next most prevalent with numbers ranging from 6 to 122 and 9 to 105 cfu/100 ml, respectively. Fifty four percent of the samples yielded Salmonella spp. at numbers ranging from 2 to 90 cfu/100 ml. Total coliform (TC) and faecal coliform (FC) counts were found in 68-100% and 76-100% of samples of individual brands, at numbers ranging from 5 to 213 and 3 to 276 cfu/ 100 ml, respectively. According to WHO standards 60-88% of samples from six brands and 32% and 40% of samples from two other brands belonged to the intermediate risk group with FC counts of 100-1000 cfu/ 100 ml. Heterotrophic plate counts, however, were under the permissible limit in all 225 samples. These findings suggest that carbonated soft drinks commercially available in Bangladesh pose substantial risks to public health.

Study was conducted to check the distribution and antibiotic susceptibility of Vibrio cholerae fr... more Study was conducted to check the distribution and antibiotic susceptibility of Vibrio cholerae from poultry and poultry environment of Bangladesh. Isolated strains were identified following standard cultural, morphological, biochemical and serological agglutination tests. Selected V. cholerae isolates were subjected to 11 antibiotics using disc diffusion method to test sensitivity. V. cholerae was recovered in 24 (9.6%) samples out of total 250. From each 50 samples of cloacal swab, intestinal fluid, egg surfaces and hand wash of chicken handlers, a total of 8 (16%), 12(24%), 3(6%) and 1(2%) samples, respectively, were detected positive for Vibrio. All of the tested Vibrio strains from poultry sources were found highly sensitive to Gentamicin, Norfloxacin and Neomycin, but were resistant to Penicillin, Ampicillin, Kanamycin, Erythromycin, Tetracycline and Rephampicin. Strains of V. cholerae in this study also exhibited both resistant and susceptible feature against Cephalexin and Streptomycin. 60% of the V. cholerae isolates were resistant to Cephalexin and Streptomycin. Rest 40% strains showed intermediate resistance to Cephalexin and sensitivity to Streptomycin. Attention must be paid for hygiene in processing and handling of poultry and poultry products, judicious application of antibiotics in treating diseases caused by V. cholerae and reduction in antibiotic use in poultry farming.

Bangladesh Journal of Botany, 1970

Advances in Environmental Biology, 2009

Isolation and identification of Vibrio cholerae from poultry and poult ry e n v ironment of Bangl... more Isolation and identification of Vibrio cholerae from poultry and poult ry e n v ironment of Banglades h were made to check their distribution and susceptib ility to selected antimirobials. Isolated strains were identified following standard cultural and biochemical tests followed by confirmation with latex agglutination test of s everal polyvalent s era. To examine the antibiotic s ens itivity, s e lected is olates of Vibrio cholerae s trains were sub jected to d isc diffusion method of 11 antibiotics. A total of 250 samples from five different sources of p o u ltry an d p o u ltry p ro d u c t s w e r e an aly zed to d etect th e incid en ce o f ch o lera o rg an is m Vibrio cholerae and a total of 24 (9.6%) samples were found as pos itive for V. cholerae d etectio n. Fro m each 50 s amp les o f cloacal s wab, intes tinal fluid, egg s urfaces , and hand was h of chicken handlers, a total of 8 (16%), 12(24%), 3(6%), and 1(2%) samples were detected as positive. All of the tested Vibrio s trains from poultry s ources were fo u n d h ig h ly s en s itiv e to Gen tamicin , No rflo xacin an d Neo my cin , b u t w e re res is tan t to Pen icillin , A mp icillin , Kanamycin, Erythromycin, Tetracycline and Rephampicin. Strains of V. cholerae in this study also exhib ited both resistant and susceptible feature against Cephalexin and Streptomycin. 60% of the V. cholerae isolates were found resistant to Cephalexin and Streptomycin. Rest 40% of isolated strains showed intermediate resistance to Cephalexin and s en sitivity to Streptomycin. This study concludes with suggestion for increased attention to be paid to the personal hygiene, processing and handling of poultry and poultry products, reduced utilization of antibiotics and appro p riate an d judicious use of antibiotics for treatment of diseases caused by V. cholerae.

Stamford journal of microbiology, Jun 4, 2013

Applied Microbiology and Biotechnology, Oct 31, 2003

The genes encoding two conjugated polyketone reductases (CPR-C1, CPR-C2) of Candida parapsilosis ... more The genes encoding two conjugated polyketone reductases (CPR-C1, CPR-C2) of Candida parapsilosis IFO 0708 were cloned and sequenced. The genes encoded a total of 304 and 307 amino acid residues for CPR-C1 and CPR-C2, respectively. The deduced amino acid sequences of the two enzymes showed high similarity to each other and to several proteins of the aldo-keto reductase (AKR) superfamily. However, several amino acid residues in putative active sites of AKRs were not conserved in CPR-C1 and CPR-C2. The two CPR genes were overexpressed in Escherichia coli. The E. coli transformant bearing the CPR-C2 gene almost stoichiometrically reduced 30 mg ketopantoyl lactone/ml to Dpantoyl lactone.

Social Science Research Network, 2013

An experiment was conducted at the Department of Botany, Jahangirnagar University, Dhaka, Banglad... more An experiment was conducted at the Department of Botany, Jahangirnagar University, Dhaka, Bangladesh to mitigate arsenic from soil by using phytoremediation process during the period from October 2012 to April 2013 following Completely Randomized Design (CRD) with three replications. Four non edible fern (viz. V1, Adiantum sp; V2, Microlepia sp; V3, Pteris vittata and V4, Christella sp) and four soil arsenic concentrations (viz. A0, Control; A1, 1000-ppm; A2, 2000-ppm and A3, 4000-ppm) were exploited. Pteris vittata L. was found as the arsenic hyperaccumulating plant. It can survive with a very high concentration of arsenic in soil and accumulate 27829.7-ppm, 23274.7-ppm and 14911.0ppm arsenic when soil was treated with 4000-ppm, 2000-ppm and 1000-ppm arsenic respectively. On the other hand other fern species used in the experiment could not survive in soil treated with arsenic. Throughout the experimental period, different growth parameters of fern species showed distinct variation with increasing concentration of arsenic. Phytoremediation of arsenic by using Pteris vittata is a possible way for the mitigation of arsenic form soil which can keep away of arsenic pollution in food chain.

Microbiological quality of drinking water of Jahangirnagar University was studied. In the disease... more Microbiological quality of drinking water of Jahangirnagar University was studied. In the disease prone, humid, tropical region of Bangladesh, outbreaks of diarrheal diseases, often in an epidemic scale, are not unusual. Samples were collected from water tap of different academic buildings, Student dormitories, small food shops that developed in the campus, etc. The HPC (Heterotrophic Plate Count) ranged from 486 to 665 cfu/ml, from 298 to 1520 cfu/ml, and from 372 to 1002 cfu/ml for the water samples collected from the sampling sites respectively. None of the samples were found compliant with microbiological standards as recommended by the World Health Organization (WHO) in terms of total coliform counts (TCC). The ranges of TCC were 2-0.52x10 2 cfu/100ml, 2-8.94x10 2 cfu/100ml, and 5-2.56x10 2 cfu/100ml in case of academic buildings, student dormitories, and food shops respectively. The average TCC and Fecal Coliform Count (FCC) were worst in the case of food shops and the better case was for academic buildings.

Oriental Pharmacy and Experimental Medicine, 2009

The pharmacological interest coupled with traditional uses (antidiarrhoeal, antiseptic, analgesic... more The pharmacological interest coupled with traditional uses (antidiarrhoeal, antiseptic, analgesic etc) prompted us to test for anti-inflammatory, antinociceptive and diuretic activitities of Trema (T.) orientalis Linn. The crude methanolic leaves extract of T. orientalis was investigated for its possible anti-inflammatory activities using carrageenin induced rat paw edema model and cotton pellet implantation method in mice. Then the extract analyzed for its antinociceptive activities by acetic acid induced writhing model in mice. The extract possessed significant anti-inflammatory activity in both models at the doses of 200 and 400 mg/kg body weight of mice. Moreover, the extract showed significantly reduced the number of acetic acid-induced abdominal constriction in mice of 200 and 400 mg/kg body weight. The extract also showed positive diuretic activity in albino mice.

Five strains of Azospirillum were isolated from rice root samples, three (N 2 , N 18 , & N 21) of... more Five strains of Azospirillum were isolated from rice root samples, three (N 2 , N 18 , & N 21) of which were identified as Azospirillum brasilense, and other two (N 5 & N 15) as Azospirillum amazonense. All strains preferred malate as their sole carbon source in medium for nitrogen fixation. Mannitol was used by only two strains, and galactose by another strain for considerable amount of nitrogen fixation. Nitrogen fixing potential in all strains was found to be gradually decreased with increasing concentration of heavy metals. But, a stimulatory effect at a low concentration of Hg was noticed in the strain N 21. A sharp difference in the behaviour pattern of heavy metals at even same concentration on nitrogen fixing potential and nitrogen dependent growth of Azospirillum strains was recorded in this study. All strains increased growth of rice seedlings significantly with a range of 29.6-95% increase over control.

Bioscience Biotechnology and Biochemistry

Publication details, including instructions for authors and subscription information: Koga (2014)... more Publication details, including instructions for authors and subscription information: Koga (2014) Characterization of a yam class IV chitinase produced by recombinant Pichia pastoris X-33, Bioscience, Biotechnology, and Biochemistry, 78:2, 222-230,

International Journal of Food Microbiology, 2009

Bioscience, Biotechnology, and Biochemistry, 2014

A yam (Dioscorea opposita Thunb) class IV chitinase, whose genomic DNA was cloned by Mitsunaga et... more A yam (Dioscorea opposita Thunb) class IV chitinase, whose genomic DNA was cloned by Mitsunaga et al. (2004), was produced by the recombinant Pichia pastoris X-33 in high yields such as 66 mg/L of culture medium. The chitinase was purified by column chromatography after Endoglycosidase H treatment and then characterized. It showed properties similar to the original chitinase E purified from the yam tuber reported by Arakane et al. (2000). This Pichia-produced chitinase also showed strong lytic activity against Fusarium oxysporum and Phytophthora nicotianae, wide pH and thermal stability, optimum activity at higher temperature such as 70 °C, and high substrate affinity, indicating that one can use this Pichia-produced yam chitinase as a bio-control agent.

Handling of paper currency notes might be a regular means of exposure to microbiological contamin... more Handling of paper currency notes might be a regular means of exposure to microbiological contamination. To assess the extent of bacterial contamination of Bangladeshi paper currency notes (known as Taka) in circulation, a total of 540 notes of three denominations (2, 10 and 100) were collected from different occupational groups and were subjected to bacteriological analysis. Among the notes examined, 506 (93.70%) were found to be contaminated with 5 different bacterial isolates. The load of Salmonella spp., Shigella spp., Vibrio spp., Pseudomonas spp. and Staphylococcus spp. ranged between 0 to 2.49×10 8 cfu/cm 2 , 0 to 1.50×10 8 cfu/ cm 2 , 7.7×10 7 to 1.59×10 9 cfu/cm 2 , 4.5×10 7 to 8.24 ×10 8 cfu/cm 2 and 3.6×10 7 to 1.32 ×10 7 cfu/cm 2 , respectively. Furthermore, 200 bacterial isolates were tested for their resistance against 10 commonly used antibiotics and 20-86% Salmonella, 8-96% Vibrio, 16-82% Pseudomonas and 18-82% Staphylococcus isolates were found to be resistant agains...

Stamford Journal of Microbiology, 2013

Present study was conducted to determine the levels of Salmonella spp. mediated contamination in ... more Present study was conducted to determine the levels of Salmonella spp. mediated contamination in samples collected from poultry and poultry environments in Bangladesh and to determine the antibiotic resistance trait in those pathogens. A total of 300 samples were collected from five different sources (cloacal swab, intestinal fluid, egg surface, hand wash of chicken handler and soil of chicken market) and 80 (26.6%) samples were found to be contaminated with Salmonella spp. One hundred and fifty Salmonella strains were isolated among which, 91 were detected as S. enteriditis and 59 as S. typhimurium through morphological, biochemical and serological tests. Susceptibility of the isolates against 13 antimicrobials was tested, and resistance against chloramphenicol (30 ?g), erythromycin (15 ?g), ampicillin (10 ?g), riphampicin (5 ?g), cephalexin (15 ?g), cefixine (5 ?g), penicillin (10 ?g), tetracycline (30 ?g), norfloxacin (10 ?g), nalidixic acid (30 ?g) and ciprofloxacin (10 ?g) was ...

Bangladesh Journal of Microbiology, 2008

The distribution and abundance of Azotobacter as well as heterotrophic bacteria in root, rhizosph... more The distribution and abundance of Azotobacter as well as heterotrophic bacteria in root, rhizosphere soil and non-rhizosphere soil samples from various wheat fields of four different areas under three districts were investigated in this study. The potential for nitrogen-fixation of five Azotobacter isolates was also detected. All samples tested were positive in their capacity to harbouring Azotobacter with a range of 26-100%. The population of heterotrophic bacteria ranged from 2.1 x 107 to 1.2 x 108 cfu/g sample. Ranges of total number of Azotobacter in different samples were 5.2 x 104 to 7.2 x 104 cfu/g, 17.2 x 104 to 25.5 x 104 cfu/g, and 12.4 x 104 to 16.7 x 104 cfu/g respectively for root, rhizosphere soil and non-rhizosphere soil. A positive correlation was found in Azotobacter colonization between root and rhizosphere, but it was negative in case of the population between heterotrophic bacteria and Azotobacter in rhizosphere. The highest amount of N was found to be fixed by t...

Bioscience, Biotechnology, and Biochemistry, 2001