Open Access Original Research Article

Antimicrobial Activities of Essential Oils from Some Medicinal and Aromatic Plants

D. Kubmarawa, M. I. Kidah, M. H. Shagal

Biotechnology Journal International, Page 1-6
DOI: 10.9734/BBJ/2016/24290

This research work was designed to examine the antimicrobial activities of some medicinal and aromatic plants. The essential oils of Adansonia digitata, Arachis hypodaea, Capsicum frutecens, Gossypium hirsutum, Hisbiscus esculentus, Nicotiana tabacum L., Piliostigma reticulatum Hochst, Sesamum alatum thoning, Solamum incanum L., Vernonia amygdalin and Vigna unguiculata were extracted by hydro-distillation and the oils were evaluated against some microorganisms. Among the plants tested, essential oils from Vigna unguiculata showed activity against all the tested microorganisms except Bacillius subtilis with minimum inhibition of 75 mm each. Piliostigma reticulatum Hochst showed activity against Staphylococcus aureus, Escherichia Coli, Pseudomonas aeruginosa, Candida albicans with minimum inhibition of 100 mm each. Sesamum alatum Thoning showed activity against Staphylococcus aureus, Pseudomonas aeruginosa and Proteus mirabilis  with minimum inhibition of 100 mm each. The activities of the essential oils against the tested organisms may be responsible for the assumed therapeutic uses of the plants by the traditional healers.

Open Access Original Research Article

Determination of Phenolic Contents, Antioxidant and Antibacterial Activities of Strawberry Tree (Arbutus unedo L.) Leaf Extracts

Abdelhakim Bouyahya, Naima El Moussaoui, Jamal Abrini, Youssef Bakri, Nadia Dakka

Biotechnology Journal International, Page 1-10
DOI: 10.9734/BBJ/2016/26488

Aims: This study was designed to evaluate the antibacterial and antioxidant activities of methanolic, ethanolic, ethyl acetate and n-hexanic extract from the leaves of Strawberry tree (Arbutus unedo L.) growing in Morocco.

Study Design: Determination of total phenol and flavonoids content, in vitro antioxidant activity and antibacterial study of extracts.

Place and Duration of Study: Department of Biology (Faculty of Sciences), between July 2015 and November 2015.

Methodology: The extracts were prepared using solid-liquid extraction. The total phenolic content was assessed by the Folin-Ciocalteau assay, total flavonoid content was assessed by aluminium chloride (AlCl3) colorimetric assay. The antibacterial activity of extracts was tested against five reference strains, Escherichia coli K12 MBLA, Staphylococus aureus CECT 976, Listeria monocytogenes serovar 4b CECT 4032 and Pseudomonas aeruginosa IH using the agar well diffusion method and the micro-dilution assays. The antioxidant activity was assessed by measuring the ability of the extracts to scavenge the 2,2-diphenyl-1- picrylhydrazyl (DPPH).

Results: The total phenol content of strawberry tree five extracts ranged between 94.51±0.08 and 141.72±0.56 mg GAE/g extract, and the flavonoid content ranged between 17.48±1.02 and 31.61±0.59 mg QE/g extract. All of the extracts presented antioxidant capacity assessed by DPPH scavenging method, but at different levels depending on the concentration and the extraction solvent are found. In addition, all extracts exhibited an antibacterial activity at different levels against strains reported as the causal agents of food borne diseases.

Conclusion: Results suggest the potential use of tested A. unedo extracts as bio-preservatives in the functional food industry.

Open Access Original Research Article

Ex-situ Conservation of the Rare and Threatened Medicinal Climber Corallocarpus epigaeus Rottler through In vitro Regeneration Method

Jai Prakash Narayan

Biotechnology Journal International, Page 1-10
DOI: 10.9734/BBJ/2016/27229

Aims: To develop in vitro propagation and callus induction protocol for regeneration and conservation of the rare and threatened medicinal climber, Corallocarpus epigaeus, which is widely acclaimed for high medicinal values.

Place and Duration of Study: The plant was spotted on Nag Pahar hill forest of Ajmer district of Rajasthan, India. Its natural regenerative potential and exploitative practices by human beings were studied during November, 2012 to December, 2013. In vitro regeneration experiments were conducted during January, 2014 and January, 2016 at Regional Institute of Education, Ajmer.

Methodology: The organogenic and callus induction potential of various parts of the plant            C. epigaeus were assessed through in vitro cultures. Murashige and Skoog`s (MS) media supplemented with various concentrations and combinations of 6-Benzyladenine (BA), Indole-3-acetic acid (IAA), α-Naphthaleneaceticacid (NAA), and Indole-3-butyric acid (IBA) were used  for enhanced axillary branching, callus induction, and rooting of microshoots. Acclimatization of rooted plantlets and their successful establishment to the soil conditions were also studied.    

Results: An efficient plant regeneration system has been developed through enhanced axillary branching which was initiated from nodal segments cultured on MS medium supplemented with various concentrations of BA, and IAA in combination. The maximum number of shoots 8.41±0.29 with average length of 6.29±0.32 cm per explant was achieved in MS medium containing 0.5 mg/L BA and 2.0 mg/L IAA. The best callus induction from stem and leaf explants was obtained on MS medium containing 2.0 mg/L (BA) and 0.5 mg/L NAA. Rooting of microshoots was achieved on half-strength MS medium supplemented with 1.0 mg/L IBA. Well developed plantlets transferred to the soil conditions showed 67% survival.

Conclusion: The methodology is reliable and highly beneficial for ex situ conservation, maintenance of in vitro biodiversity and multiplication of the Great Root for commercial production of tubers of diverse pharmacological properties.   

Open Access Original Research Article

Studies on the Proximate, Functional and Antioxidant Properties of Fermented and Unfermented Kariya (Hildergardia barterii) Seed Protein Hydrolysates Obtained by Enzymatic Hydrolysis

Olasunkanmi S. Gbadamosi, Albert A. Famuwagun

Biotechnology Journal International, Page 1-14
DOI: 10.9734/BBJ/2016/26685

The degree of hydrolysis (DH), proximate composition, functional properties and anti-oxidative characteristics of enzymatic kariya seed hydrolysates were evaluated with a view to increasing the utilisation of the seed as food ingredient. Protein hydrolysates were obtained from fermented and unfermented kariya seed protein isolate using two proteolytic enzymes: Pepsin and pancreatin to obtain fermented pancreatin kariya protein hydrolysate (FPcKPH), unfermented pancreatin kariya protein hydrolysate (UPcKPH), fermented pepsin kariya protein hydrolysate (FPsKPH) and unfermented pepsin kariya protein hydrolysate (UPsKPH). The results showed that pancreatin hydrolysates had higher degree of hydrolysis (FPcKPH; 65.20% and UPcKPH; 50.50%) than pepsin hydrolysates (FPsKPH; 53.00% and UPsKPH; 33.93%) while the fermented hydrolysates showed higher DH than the unfermented hydrolysates both in the pancreatin and pepsin hydrolysates. The results also showed that fermented hydrolysates had better functional properties than the unfermented samples. The protein contents of the fermented hydrolysates were also improved. The antioxidant characteristics showed that fermented kariya protein hydrolysates exhibited higher DPPH (2,2-diphenyl-2-picrylhydrazyl hydrate) radical scavenging activity (FPcKPH, IC501.03; FPsKPH, IC501.40; UPcKPH, IC50 1.51; UPsKPH, IC50 6.97 mg extract/ml), metal chelating (FPcKPH, IC50 0.95; FPsKPH, IC500.53; UPcKPH, IC50 1.27; UPsKPH, IC50 1.06 mg extract/ml) and ferric reducing antioxidant power (FPcKPH, 0.63; FPsKPH,0.50; UPcKPH 0.35; UPsKPH, 0.23 AAµg/g). The study concluded that fermented kariya seeds hydrolysates could find applications as potential source of natural anti-oxidants in food.

Open Access Review Article

Role of Microorganisms in Corrosion Induction and Prevention

Rawia Mansour, Ali Mohamed Elshafei

Biotechnology Journal International, Page 1-11
DOI: 10.9734/BBJ/2016/27049

Microbiologically-influenced corrosion (MIC) is defined as the deterioration of metals as a result of metabolic activities of microbes. The biological harmful activities modify local chemistry and render it more corrosive to the metal. The aerobic iron and manganese bacteria are mainly responsible about the accelerated pitting attacks of stainless steel, however the anaerobic sulfate reducing bacteria (SRB) are responsible for most highly corrosion damages to offshore steel structures. Most MIC takes the form of pits that form below the colonies of living organic matter and mineral and the deposits of biological origin. Stainless and carbon steel tanks, pipelines, heat exchangers, fuel storage tanks are mainly affected by MIC. On the other hand, other beneficial microorganisms play a major role for protecting these surfaces from corrosion via different mechanisms including biofilms formation. The aim of this review is to present a spotlight on the history and the role of microorganisms on the induction and prevention of corrosion. This includes corrosion inhibition mechanisms employing beneficial microorganisms with special reference to microbial biofilms to avoid the dramatic economic loss due to corrosion. On the contrary, different types of harmful microorganisms included in corrosion are also discussed including iron and sulfur reducing bacteria.