Open Access Original Research Article

Effect of Selected Conditions on Spore Populations Outgrowth Dynamics and Time to Single Spore Outgrowth Distribution in Bacillus subtilis and Bacillus cereus Spores Population

F. X. Etoa, A. Nkoue Tong, J. J. Essia Ngang, S. L. Sado Kamdem

Microbiology Research Journal International, Page 1-16
DOI: 10.9734/MRJI/2017/30621

Aims: In this study the effect of sporulation conditions, namely pH, CaCl2 concentration and the type of spore activation was assessed on the population outgrowth kinetics parameters and time to individual spore outgrowth distribution of Bacillus subtilis and Bacillus cereus spores.

Place and Duration of Study: Department of Microbiology of the University of Yaoundé I between September 2014 and May 2015.

Methodology: The population outgrowth kinetics are assessed by monitoring single spores outgrowth as colony during incubation and expressed in terms of cumulative frequency. The time to single spore outgrowth distribution is obtained by fitting the Weibull exponential equation to this cumulative frequency and applying the Weibull distribution probability density function.

Results: In general, high CaCl2 and pH of the sporulation medium and sporulation temperature of 37°C compared to 25°C reduced the time within a population for the first spore outgrowth (Plag) at 37°C irrespective of the strain. Statistically, only the pH and the interaction strain and temperature significantly affected the spore outgrowth rate (p<0.05). Sporulation at 25°C and 37°C induced short tgrowth distribution means and modes for Bacillus cereus and Bacillus subtilis respectively. Moreover, the mode of tgrowthdistributions was statistically influenced by type of activation and strain (p<0.05).

Conclusion: Spore germination and outgrowth of Bacillus subtilis and Bacillus cereus depended more on sporulation conditions like pH and temperature than on levels of CaCl2 concentration used. In terms of time to single spore outgrowth distributions, 25°C sporulation temperature induced low mean and modes for Bacillus cereus while for Bacillus subtilis this occured at 37°C. The type of activation and strain significantly influence the mode of time to single spore outgrowth distribution.

Open Access Original Research Article

Screening and Characterization of Biosurfactant Producing Bacteria from Soil Samples in Ogun-State, Nigeria

S. O. Adebajo, A. K. Akintokun, S. A. Balogun

Microbiology Research Journal International, Page 1-12
DOI: 10.9734/MRJI/2017/29815

Aims: Biosurfactants are surface active compound that are synthesized by microbes like bacteria, fungi and yeast. Biosurfactant have different applications in the industries. Biosurfactant can be used as emulsifiers, as well as demulsifiers, wetting agents, foaming agents, spreading agents, food ingredients and detergents etc. Ability of the microorganisms to produce biosurfactant was carried out using different screening techniques in a stepwise process.

Study Design: Soil samples were randomly collected from 8 different automobile shops in Ogun State, Nigeria.

Place and Duration of Study: Soil samples were collected from eight different automobile shops located at Oru-Ijebu, Ago-iwoye, Abeokuta and Ijebu-ode in Ogun state, Nigeria during the rainy season in the month of July, 2015.

Methodology: Biosurfactant-producing bacterial isolates were isolated and screened for biosurfactant production using haemolytic, oil spreading, drop collapse, bacteria adhesion to hydrocarbon and emulsification index tests (E. I). Bacteria were identified using biochemical tests and best biosurfactant producer bacteria was identified by molecular techniques. Bacteria with highest emulsification potential were selected to be the best biosurfactant producer.

Results: Result of the haemolytic activity test on blood agar showed that 46 isolates (17.4%) out of the 264 isolates showed beta-hemolytic activity, 39 (84.8%) isolates out of the 46 beta haemolytic isolates were positive for oil spreading test, 33 (84.6%) isolates were positive to the drop collapse  assay and all the seventeen highly positive isolates for drop collapse test were positive  for BATH test. Pseudomonas taenensis had the highest E.I of 71.05% at 24 hrs while Acinetobacter calcoaceticus had the lowest E.I of 32.6% at 24 hrs. Isolates with highest E. I were chosen to be best biosurfactant producer and are the best choice of isolate to produce biosurfactant.

Conclusion: The present study inferred that bacterial strains of Pseudomonas taenensis showed satisfactory results in all the screening tests and can be used as a potential candidates for biosurfactant and bioemulsion production.

Open Access Original Research Article

Effect of Physicochemical Parameters on the Biodegradation of Phenanthrene by Pseudomonas aeruginosa

V. N. Yogananda Murthy, V. N. Murulidhar, M. Mahesh

Microbiology Research Journal International, Page 1-11
DOI: 10.9734/MRJI/2017/30484

Aim: Polycyclic aromatic hydrocarbons (PAHs) are categorised as potentially harmful chemicals of environmental and health apprehension. Microbial degradation is the principle practice for effective elimination and abolition of PAHs from polluted environment. Phenanthrene, a PAH compound, recalcitrant xenobiotic causes severe damage to kidney, liver, fat tissues and causes cancer. Removal of this from environmental pollutants is expensive by existing methods. To overcome this, an attempt has been made for the degradation of phenanthrene by using microorganisms.

Materials and Methods: Seven organisms were isolated from thirty six soil samples using M9 media with phenanthrene. One organism that shows highest degradation was identified by morphological and molecular (16S rRNA sequencing) analysis. Physical parameters such as incubation period, concentration, pH and temperature and chemical parameters like carbon, nitrogen and metal ion sources were used for efficient degradation of phenanthrene.

Results: Results revealed that, among the seven organisms, one organism was significantly effective in degradation and was identified as Pseudomonas aeruginosa by 16S rRNA sequence and strain kar5, accession No KT225506 was registered in National Centre for Biotechnology Information (NCBI). Maximum degradation was noticed using 100 ppm concentration at 37°C with pH 7 and 96 hr. Starch showed slightly high degradation compared to other carbon sources such as sucrose, lactose, maltose and cellulose. In nitrogen sources, tryptone revealed more degradation than casein, gelatin, egg albumin and bovine serum albumin. Metal ions like MgCl2 and ZnCl2 recoded significant degradation measured by spectrophotometer at 340 nm and confirmed by HPLC. Maximum growth of microorganism measured by spectrophotometer at 600 nm and reached to OD 0.851 ± 0.7.

Conclusion: Study confirms that, physico-chemical parameters play a significant role in degrading soil with high PAHs concentration.

Open Access Original Research Article

The Effectiveness of Recovery of Gram-positive and Gram-negative Bacteria on Sano-Gam Media

M. E. Gamer, S. M. Elsanousi

Microbiology Research Journal International, Page 1-4
DOI: 10.9734/MRJI/2017/28467

The present study was carried out to determine the recovery response of cold-shocked Gram-positive and Gram-negative bacteria on Sano-Gam media. Sano-Gam medium is an abbreviation of the two scientists names Sanousi and Gamer Aldawla. This medium consisted of; Sodium pyruvate, Mg, Cu, Fe and Zn, and cellular catalase enzyme. The catalase enzyme was extracted from fresh broth culture of E. coli bacterium and was incorporated in the media separately or in variety of combinations with sodium pyruvate and trace elements. The studied bacteria were Streptococcus spp., Salmonella spp., Proteus vulgaris and Bacillus cereus. All tested bacteria were obtained from one standard culture collection (Department of Microbiology, Veterinary Medicine, University of Khartoum). On Sano-Gam media the response of all tested bacteria to recovery were monitored and determined through sequential colony counting. Both Gram-positive and Gram-negative bacteria were found to have an excellent ability to repair their cellular damages and well recovered on Sano-Gam media, notwithstanding of their distinctive cell wall components.

Open Access Original Research Article

A Peculiar Phenomenon of Cold-shocked Bacteria Recovered on Sano- Gam Media

M. E. Gamer, S. M. Elsanousi

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/MRJI/2017/28466

This study was conducted in order to display the peculiar appearance of bacteria which were recovered on Sano-Gam Media. The studied bacteria were Escherichia coli, Salmonella spp., Staphylococcus aureusProteus vulgaris and Klebsiella pneumoniae. Some of the tested bacteria recovered on SANO-GAM media reflected peculiar growth appearance which had been noticed as high carbon dioxide production by Salmonella spp., in Glucose medium. A huge mist growth of P. vulgaris, spider network and crystal manifestation of E. coli colonies, strange accumulation of K. pneumoniae on Cu Sano-Gam medium were observed as button-like colonies of Salmonella spp., and ferrum stained colonies of E. coli were seen. From the positive point of view the new invented Sano-Gam media were being able to recover all tested bacteria nicely irrespectively whether they have expressed their growth peculiarly or not.

Open Access Short Research Article

Microbial Count of Non-sterile Pharmaceutical Products Sold in Pakistan

Yasir Mehmood, Noviara Saleem, Hammad Yousaf, Syed Saeed-ul-Hassan, Javed Iqbal

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/MRJI/2017/28524

Aims: To explore the microbiological quality of tablets in blister-packed, manufactured and marketed in Pakistan in order to assess Good Manufacturing Practice (GMP) by national and multinational pharmaceutical industries in the country.

Methods: For this research we have purchased 50 different tablets (registered brands) blister-packed from community pharmacies in Lahore. 15 products brands were multinational, 15 were national and 20 brands were from local pharmaceuticals. All these tablets were investigated for total bacterial count and the presence of specified microorganism (Escherichia coli) using compendial procedures. In order to determine batch to batch variation in the numeric data obtained for the 3 packs purchased for each brand, statistical analysis to establish the deviation from the mean count was carried out using t- test with the aid of Sigma Plot software. Differences were considered as statistically significance at p < 0.05.

Results: 24% of the products (12 from 50 items) showed microbial contamination within normal range while 76% products (38 items) showed microbial count out of the normal range. In 20% of the products (10 items) Escherichia coli were the most obnoxious bacteria that were found. One company manufactured a product with the high proportion of stratified bacteria especially Escherichia coli.

Conclusion: Our study showed that blister-packed tablets produced by Pakistani pharmaceutical companies are within acceptable microbiological quality but the detection of microbial load in some brands were very close to the maximum allowable limit,. However, we observed that some local brands 24% are not within acceptable range of microbes. Therefore, we recommend the need for improved adherence to GMP in the country.