Open Access Original Research Article

Screening of Lactic Acid Bacteria Capable to Breakdown Citric Acid during Ivorian Cocoa Fermentation and Response of Bacterial Strains to Fermentative Conditions

Djeneba H. Ouattara, Honoré G. Ouattara, Jacques N. Adom, Bernadette G. Goualié1, Gisèle A. Koua, Ginette G. Doué, Sebastien L. Niamke

Biotechnology Journal International, Page 1-10
DOI: 10.9734/BBJ/2016/19279

Aims: The breakdown of citric acid contained in the pulp during cocoa fermentation is an important and key property for bacterial growth and for obtaining a well fermented cocoa. The objective of this study was to analyze citrate metabolism in lactic acid bacteria (LAB) isolated from Ivorian fermenting cocoa beans and evaluate their capacity to grow effectively under fermentation conditions.

Place and Duration of Study: Laboratory of Biotechnology, UFR Biosciences, University Félix Houphouet-Boigny (Côte d’Ivoire), between August 2014 and April 2015.

Methodology: Spontaneous heap fermentations were conducted in three cocoa producing regions during 6 days. Bacteria isolation was performed using plate culture on MRS medium and strains were screened for citrate metabolism using Kempler and McKay medium whereas gas and acetoin productions from citrate were searched. Additionally, the viability of cells under stress conditions related to cocoa fermentation was tested.

Results: The results show that a wide rate of LAB strains (75%), mainly heterofermentative possess citrate metabolism, and most of these strains produce gas from citrate but were not able to produce acetoin from citrate. Moreover, some LAB presenting citrate metabolism show a remarkable thermotolerance at 45°C with more than 50% of survival growth rate (SGR), while some exhibited a poor viability (less than 10%) at this temperature. Ethanol at 8-12% was found to have no adverse effect on bacterial growth. In contrast, lactic acid, acetic acid and citric acid exerted individually full inhibition on LAB strains that failed to grow at 0.4% of acid.

Conclusion: Taken together, the results indicate that strains studied may preferentially produce lactic acid from citrate and their high proportion should contribute to efficiently break down citric acid during cocoa fermentation. However, occurrence of a high acidity could seriously limit the growth of these valuable potential starter strains in fermentation conditions.

Open Access Original Research Article

T. thermophilus Rhamnolipids Induce Cytogenetic Damage on Human Lymphocytes and Bind DNA in vitro

Eleni Andreadou, Athina Moschopoulou, Olga Simou, Theodoros Lialiaris, Anastasia Pantazaki

Biotechnology Journal International, Page 1-12
DOI: 10.9734/BBJ/2016/21907

Aims: Bacteria including Pseudomonas and T. thermophilus secretes rhamnose–containing glycolipid biosurfactants called rhamnolipids (RLs), known as bacterial virulence factors. The aim of this investigation was the evaluation of DNA damage induced on human lymphocytes by both RLs itself, secreted in a host organism by pathogens during a bacterial attack or symbiosis and in combination with the camptothecin (CPT), and on calf thymus DNA.

Study Design: Human lymphocytes and calf thymus DNA were treated with isolated                          T. thermophilus RLs for studying DNA damage in vitro. 

Methodology: RLs DNA damaging action was evaluated by the Sister Chromatid Exchanges (SCEs) methodology, a method for estimating genotoxicity of human exposure to different chemicals or other mutagenic agents and by DNA electrophoretic mobility experiments.

Results: RLs at concentrations of 100 and 150 μg/mL reveal significant toxicity. The highest concentration of 200 μg/mL reveals higher genotoxicity. The frequency of SCEs/cell was increased two times over the control level. When CPT, an antineoplastic drug with DNA damaging action, was tested together with RLs the genotoxic activity was reduced significantly (P<0.01) compared to the action caused by CPT itself. Sequential increase in the concentration of RLs results in the proportional reduction of Proliferation Rate Index (PRI) which is a cytostatic index. Also, Mitotic Index (MI), a cytotoxic index, was also significantly decreased at concentration of 200 μg/mL RLs. Addition of RLs in the same concentration together with CPT doesn’t affect the MI so much. Moreover, RLs are obviously capable for strong binding to plasmid or calf thymus DNA in vitro.

Conclusion: RLs exert genotoxicity, cytotoxicity and cytostaticity in human lymphocytes and play probably a protective role for cells against CPT due to RLs’ detergent capability to enrobe CPT and DNA, providing a significant property that might support its possible involvement in DNA horizontal transfer phenomena.

Open Access Original Research Article

Reproductive Characteristics of Rabbit Bucks Fed Diet Containing Raw or Fermented Cottonseed Cake

O. A. Amao, K. A. Showunmi

Biotechnology Journal International, Page 1-7
DOI: 10.9734/BBJ/2016/15383

This study was conducted to investigate the effect of diets containing raw or fermented cottonseed cake on reproductive characteristics of rabbit bucks. Eighteen (18) weaned crossbred (New Zealand White X Chinchilla) rabbit bucks, 6-7 weeks old, were randomly allotted to three treatments with six animals per treatment in a Completely Randomized Designed experiment. The treatment diets were T1, (Control) containing soyabean meal (SBM) as the main protein source; T2, Raw Cottonseed Cake (RCSC) - based diet and T3, Fermented Cottonseed Cake (FCSC) - based diet. The fermentation was done by inoculation with Aspergillus niger. Animals were acclimatized for one week. The feeding trial lasted for 9 weeks. At the end of this trial, 3 bucks per treatment were slaughtered and the reproductive organs dissected out for testicular and epididymal morphometrics as well as gonadal sperm assessment. Testicular morphometrics were not significantly (P>0.05) affected by the treatment. Treatment had significant (P<0.05) effect on the epididymal weight and length of rabbit buck. Testicular sperm count for the RCSC group (124.67x106) was significantly (P<0.05) lower than that of the control (182.22x106). Bucks on FCSC diet had comparable sperm count (181.50x106) with the control group. The proportion of motile sperm was significantly (P<0.05) increased from 48% in the control to 66.33% in the FCSC group. It was concluded that raw CSC had adverse effect on the sperm characteristics of rabbit bucks. However fermentation, using Aspergillus niger mitigated the adverse effect of CSC on the sperm characteristics. It is recommended that CSC to be included in diet of rabbit bucks meant for breeding purpose should be fermented by Aspergillus niger.

Open Access Original Research Article

Spectrophotometric Determination of Sun Protection Factor and Antioxidant Potential of an Herbal Mixture

Madhulika Singh, Varsha Sharma

Biotechnology Journal International, Page 1-8
DOI: 10.9734/BBJ/2016/21434

Objectives: Present research work deals with the determination of hydroxyl radical scavenging potential and Sun Protection Factor of herbal mixture which was prepared by the phytochemical composition of different herbal extracts.

Materials and Methods: The herbal mixture was prepared by the composition of important herbal plant extracts such as; 50% ethanolic extract of Berberis aristata  root, 30% ethanolic extract of Ficus benghalensis bark, ethanolic extract of Asparagus racemosus root, aqueous extract of Asparagus racemosus root, 30% methanolic extract of Butea monosperma flowers, gel extract of Aloe vera, 80% ethanolic extract of Terminalia arjuna  bark, 80% ethanolic extract of Cyperus rotundus root, 80% ethanolic extract of Rubia cordifolia root and 50% methanolic extract of Hibiscus-rosa-sinensis flowers, which was further proceed for hydroxyl radical scavenging activity and Sun Protection Factor determination at different concentrations viz;0.5%, 1%, 5% and 10%.

Results: IC50 values of Ascorbic acid was found to be 52.93±2.64% (Inhibition TBARS) at the concentration of 18.00 µg/ml and herbal mixture were 51.58±1.27% (Inhibition TBARS) observed at the concentration of 9.80 µg/ml respectively. The SPF values for different concentrations of herbal mixture were in between 2.14±0.15SPF to 12.97±0.07SPF. The results showed that 10% concentrated of herbal mixture has high SPF value of 12.97±0.07SPF which may be attributed due to the presence of active components.

Conclusion: Herbs and herbal preparations have high potential due to their antioxidant activity, primarily. The bioactive compounds such as flavonoids, phenolic acids, saponins etc. of this prepared herbal mixture may able to reduce skin damages which are caused due to long time exposure of skin in sun rays specially UVA and UVB rays. The proposed spectrophotometric method is simple and rapid for the in vitro determination of SPF values of sunscreens emulsions.

Open Access Original Research Article

Molecular Characterization of Some Virulence Factors of Streptococcus pneumoniae Isolated from Children with Acute Otitis Media in Hilla, Iraq

Lamees Abdul-Razzaq Abdul-Lateef, Safaa H. Alturaihy, Shaima A. Alabass. M. Al-Taai

Biotechnology Journal International, Page 1-11
DOI: 10.9734/BBJ/2016/22033

Aims: Isolation and identification of Streptococcus pneumoniae from children with acute otitis media. Molecular detection of some virulence genes of S. pneumoniae such as pneumolysin (ply), autolysin A (LytA), Neuraminidase (NanA), Luminescence luxS, capsular polysaccharide synthesis (cpsA), pneumococcal surface antigen A (psaA), α- Enolase (Eno ) by using PCR primer.

Place and Duration of Study: Hilla Teaching Hospital (ENT unit) and privacy during a period from November (2014) to March (2015), Hilla, Iraq.

Methodology: A total 0f 120 Ear swabs obtained from children suffering from acute otitis media ranged from (1 months - 12 years). Only eight isolates of S. pneumoniae were isolates. Seven virulence genes were investigated in eight clinical isolates of S. pneumoniae by using PCR techniques.

Results: Pneumolysin and autolysin were seen to be present in only 4 isolates which were isolated from otitis media samples, whereas Luminescence and α - Enolase gene  were present in five isolates, Besides, Neuraminidase and pneumococcal capsule synthesis A were detected in all isolates. It was found that Pneumococcal Surface antigen A is present in 2 isolates.