Open Access Original Research Article

Optimization of Phenolics and Carotenoids Extraction from Leaves of Passiflora edulis Using Response Surface Methods

K. D. P. P. Gunathilake, K. K. D. S. Ranaweera, H. P. V. Rupasinghe

Asian Journal of Biotechnology and Bioresource Technology, Page 1-12
DOI: 10.9734/AJB2T/2017/33480

The optimum extraction conditions for the highest recovery of total phenolics and carotenoids contents for leaves of Passiflora edulis were developed using response surface methodology. The effects of solvent concentration (30-100%), extraction temperature (30-60°C) and extraction time (30-90 min) on the recovery of total phenolics and carotenoids were investigated. A second order polynomial model produced a satisfactory fitting of the experimental data with regard to total phenolics (R2 = 84.75%, p < 0.004) and carotenoid (R2 = 78.74, p < 0.019) contents. The optimum extraction conditions of ethanol concentration, extraction temperature and extraction time for phenolics, were 6.1%, 70.2°C, and 110.5 min and for carotenoids, the optimum parameters were 100%, 70.2°C and 110.5 min, respectively. The optimal predicted contents for total phenolics (9.03 mg Gallic Acid Equivalent (GAE)/ g DW) and carotenoids (8.74 mg/g DW) values in the extracts were agreed with the experimental values obtained with optimum extraction conditions for each response.

Open Access Original Research Article

Effect of Chitosan Coating on the Post Harvest Quality of Banana during Storage

Shaik Mohammed Zahoorullah, Lomada Dakshayani, A. Swaroopa Rani, G. Venkateswerlu

Asian Journal of Biotechnology and Bioresource Technology, Page 1-10
DOI: 10.9734/AJB2T/2017/34732

Chitosan-based coating was concerned in recent years owing to its non-toxic, biodegradable, and biocompatible. The objective of the study was to evaluate the effect of Chitosan coatings that were applied by double immersion of fruits in the film-forming solutions for 5 min, depending on treatments: (i) Chitosan at 1.5% (w/v) in lactic acid 1% (v/v); (ii) Chitosan at 1.5% (w/v) in lactic acid 1% (v/v) and Tween 80 at 0.1% (w/v); and (iii) Chitosan at 1.5%(w/v) in acetic acid 1% (v/v). (iv) uncoated. The effectiveness of the treatments in extending fruit shelf-life was evaluated by determining ripening stages, weight loss, firmness, pH, total sugars, reducing sugars, non- reducing sugars.

The results have proved that the addition of Lactic acid at 1% (w/v based on chitosan) and Tween 80 at 0.1% (v/v) in chitosan solution improved coating properties delaying the ripening stage with lowest weight loss (4.5%), lowest firmness (38%), with no change in pH (4.8-4.9), high total sugars (95%), high reducing sugars (46%) and low  non-reducing sugars (45%) in banana.

Open Access Original Research Article

Rapid Biodegradation of Phenanthrene by a Novel Strain Pseudomonas denitrificans Fdl

A. Astanin, S. Zagrebelny, A. Alekseev, A. Alekseev, L. Adamenko, V. Morozova, I. Andreeva, M. Selivanova

Asian Journal of Biotechnology and Bioresource Technology, Page 1-10
DOI: 10.9734/AJB2T/2017/34914

Aims: The aim of the study was to find, isolate, identify and characterize a phenanthrene degrader strain, and examine its ability to degrade phenanthrene.

Place and Duration of Study: Faculty of Natural Sciences, Novosibirsk State University, between September 2013 and June 2014.

Methodology: Soil was sampled from the oil contaminated area in the Purov district of the Yamal-Nenetsk Autonomous region in Russia (63.00729 NL, 76.89418 EL), and the enriched culture of oil-degraders was spread on plates with polyaromatic hydrocarbons (PAH) to isolate PAH degraders. The isolated strain was characterized morphologically, biochemically, physiologically and genetically (16S rRNA gene nucleotide sequence).

Results: By using crude oil-contaminated soil to obtain a culture enriched with oil-degraders followed by plate cultivation on phenanthrene-amended agar a bacterial strain denoted Fdl was isolated. Its cells were Gram-negative motile rods 0.4-0.5 µm wide and 1.5-2.5 µm long with phenotypic traits common for the Pseudomonas genus. The 16S rRNA gene fragment nucleotide sequence showed 99% similarity with Pseudomonas denitrificans. The isolated Pseudomonas denitrificans Fdl strain was deposited into the GenBank under access number KM 436103. Incubation of the Fdl strain cells in the medium with phenanthrene as a sole carbon source resulted in phenanthrene concentration decrease, accumulation of corresponding metabolites and bacterial proliferation, which confirmed the strain’s ability to utilize phenanthrene. Over 40 hours of incubation the phenanthrene concentration decreased from 100 to 1 ppm, proving the novel strain to be an effective phenanthrene degrader. Addition of Tween-20 non-ionic surfactant into the incubation medium accelerated phenanthrene degradation and cell proliferation as compared to phenanthrene degradation without a surfactant.

Conclusion: The isolated strain Pseudomonas denitrificans Fdl is capable of efficient phenanthrene degradation, especially in the presence of detergent, and hence can be a good candidate for biological preparations to be tested for bioremediation and sewage sludge treatment.

Open Access Original Research Article

Nutritive Compounds from Flours of Borassus aethiopum New Shoots Enriched with Moringa oleifera Leaves and Vigna unguiculata Beans Powders

Mahan Makado Romuald, Konan N’guessan Ysidor, Deigna-Mockey Viviane, Sidibe Daouda, Coulibaly Adama, Assi Yapo Olivier, Biego Godi Henri Marius

Asian Journal of Biotechnology and Bioresource Technology, Page 1-14
DOI: 10.9734/AJB2T/2017/34066

The objective of this study is to contribute to a better valorisation of Palmyra by determining the nutritive compounds of the flours of its young shoots enriched with Moringa oleifera leaves and Cowpea beans powders, also evaluate the nutritional contributions of the consumption. The samples were collected between August and December 2015 from 3 big regions (Bélier, N’Zi and District of Yamoussoukro), in the center of Côte d’Ivoire. Once acquired, from the samples, 250 Kg, 75 Kg and 75 Kg of Palmyra new shoot tubers, cowpea beans and moringa leaves respectively, were sorted, washed dried and processed into flour. For this purpose, the nutritive compounds of formulations obtained using the central composite design and two industrial infantile flours (ET1 and ET2) were determined. The analysis of the nutritive compounds gave the following contents: proteins (8.27 ± 0.09 – 15.07 ± 1.74 g/100 g), ash (1.65 ± 0.23 - 2.67 ± 0.20 g/100 g), lipids (1.33 ± 0.18 - 8.70 ± 1.71 g/100 g), carbohydrates (68.07 ± 0.48 – 82.13 ± 0.96 g/100 g), soluble carbohydrate (4.55±0.37 - 30.71±1.27 g/100 g), reducing sugars (0.97±0.08 -8.07±0,48 g/100 g), and fibers (1.58±0.09 – 5.50±0.19 g/100 g). Of the formulations, nine had high protein content to that of the control flour ET1 and therefore had protein values in accordance with the FAO/WHO recommended standards for weaning foods. The caloric energy values of these flours are high (301.43 ± 3.80 to 352.58 ± 0.50 kcal/100 g). The average daily quantity of flour consumed by children under 5 in Africa is 250 g. The contributions estimated in nutritive compounds of 250 g of EF07 or EE09 flours are higher than those obtained with B. aethiopum flour. They contributed to more than 100% of needs in proteins and caloric energy, and 50% of fibers in children under 5. Similar results are obtained with the reference flours used. The popularization of these composite food formulations could help to ensure the food security of populations, preserve biodiversity and promote the fight against poverty and the advancement of the desert.

Open Access Original Research Article

Plasmid – mediated Resistance in Salmonella typhi Isolates from Door Handles in Nasarawa State, North-central Nigeria

S. A. Mohammed, P. A. Tsaku, I. H. Nkene, V. B. Oti, I. K. Ekeleme

Asian Journal of Biotechnology and Bioresource Technology, Page 1-12
DOI: 10.9734/AJB2T/2017/34780

Contamination of door handles with antibiotic resistant bacteria can be a major threat to public health, as the antibiotic resistant determinants can be transferred to other pathogenic bacteria thus, compromising the treatment of severe bacterial infections. This study investigated the antibiotic susceptibility and plasmid profile of Salmonella typhi isolated from door handles of two tertiary institutions in Nasarawa State, Nigeria. One hundred door handles from each of the two institutions, making 200 in total were sampled and 36(18.00%) S. typhi were isolated. The isolates were 100% resistant to 7 out of the 10 antibiotics tested. Minimum Inhibitory Concentrations (MICs) study on selected multiple antibiotics resistant isolates showed that the isolates were susceptible to the tested antibiotics in the following order: Imipenem = Ciprofloxacin > Ceftazidime > Cefuroxime > Ampicillin > Nitrofurantoin. Fourteen (38.89%) of the multiple antibiotic resistant isolates produced beta lactamase enzymes. Conjugation experiment on the multiple antibiotics resistant S. typhi isolates showed that 7(18.42%) of the test S. typhi isolates transferred resistance plasmid gene to sensitive Proteus mirabilis and the MICs of the recipients increased significantly after conjugation. Plasmid profile of the transconjugants and the donors showed the presence of plasmid of different sizes ranging from 1600 to 2500 base pairs in both donor multiple antibiotics resistant S. typhi and transconjugants P. mirabilis. The transfer of resistant plasmids between bacteria could result in serious epidemics that may be difficult to manage.