Open Access Short Research Article

Enzyme Hydrolysis of Hydrogen Peroxide Pretreated Lignocellulosic Content of Rice Husks Prior to Bioethanol Formation

John O. Ojowu, Michael I. Ortese, Esin E. Etim

Asian Journal of Biology, Page 1-6
DOI: 10.9734/AJOB/2017/34747

Aims: This work was aimed at evaluating the production of sugar from the bio-fermentation of rice husk using hydrogen peroxide as a pre-treatment medium.

Methodology: Different samples of rice husks were pretreated with 1%, 1.5%, 2%, and 2.5% (w/v) hydrogen peroxide respectively and allowed to delignify for 2 hours prior to saccharification by cellulose at 37°C and pH of 4.7. The experiment was repeated at varying time intervals spanning 2-24 hours. Amount of reducing sugars produced was determined spectrophotometrically and documented.

Results: High reducing sugar yields at concentrations of 1%, 1.5%, and 2%, H2O2 were observed as 0.81 mg/ml with saccharification of 10.47%, 1.15 mg/ml with saccharification of 14.87%, and 1.42 mg/ml with saccharification of 18.36% respectively. Pretreatment with 2.0% H2O2 was found to achieve highest reducing sugars yield (1.42 mg/ml with saccharification of 18.36%) after pretreatment time of 8 hours as against other concentrations.

Conclusion: The result suggests that degree of saccharification is dependent on concentration of hydrogen peroxide used and time of pre-treatment. The reduction in sugar yield at 2% H2O2 may be as a result of hydrogen peroxide solubilizing lignin which may act as an inhibitor during enzyme hydrolysis.

Open Access Original Research Article

Species Composition and Relative Abundance of Mosquito Larvae in Suez Canal Zone, Egypt

Mohamed Sowilem, Manal Elshaier, Wedad Atwa, Ahmed El-Zeiny, Asmaa El-Hefni

Asian Journal of Biology, Page 1-12
DOI: 10.9734/AJOB/2017/35053

Mosquito-borne diseases have a great impact on human and animal health throughout the world, including Egypt. A survey was conducted at Suez Canal Zone for 8 months, prolonged from November 2014 till April 2016 to identify the mosquito larvae and to investigate the different breeding habitats preferences of mosquito's larvae. Larvae were collected using a standard dipping with a small ladle. A total of 14806 mosquito larvae were collected from 7 different breeding habitats and found belonging to 5 genera and 10 species; Culex pipiens L. Culex perexiguus Theobald, Culex (Barraudius) pusillus Macquart, Anopheles (Cellia) multicolor Cambouliu, Anopheles (Anopheles) tenebrosus Dönitiz, Anopheles (Cellia) pharonsis Theobald, Culiseta longiareolata (Macquart), Ochlerotatus detritus Haliday, Ochlerotatus caspius (Pallas) and Uranotaenia unguiculata Edwards. Out of these, 5 species are considered as high potential vector of diseases in Egypt. Results indicated that Cx. pipiens is the most common vector prevalent in all months representing 66.90% (n=9905 larvae) of total collection, followed by Cx. perexiguus 10.06% (n=1490 larvae). Different habitats of Suez Canal area are environmentally suitable for mosquito breeding and therefore the probability of emergence/re-emergence of the mosquito-transmitted diseases becomes enhanced. So, the present study provides the baseline information for decision makers to take necessary optimal control strategies to mitigate mosquito nuisance, proliferation rate and the areas under risk of potential diseases transmission.  

Open Access Original Research Article

Comparative Evaluation of the Effect of Annona muricata (Graviola) Leaves Extracts and Cefoxitin on Staphylococcus aureus

U. E. George, C. I. Mboto, E. N. Mbim, U. O. Edet, C. F. Umego, H. Sunday

Asian Journal of Biology, Page 1-7
DOI: 10.9734/AJOB/2017/34555

Resistance of Staphylococcus aureus to beta- lactam drugs most especially cefoxitin is a known global problem. Current researches are geared toward evaluating the antimicrobial properties of medicinal plants against these organisms. This study was aimed at comparatively evaluating the antimicrobial effects of cefoxitin and Anonna muricata (Graviola) against Staphylococcus aureus strains. A total of ten Staphylococcus aureus  strains obtained from the Microbiology Department of General Hospital were subjected to susceptibility testing against cefoxitin and Anonna muricata extracts (both aqueous and ethanol), respectively using standard microbiology techniques. Out of the 10 isolates tested, 4 (40%) showed resistance to cefoxitin, 2 (20%) were intermediate while 4 (40%) showed susceptibility. However, 8 (80%) out of 10 isolates showed susceptibility to  Annona muricata ethanol extract while 2 (20%) were resistance.  In addition, 9 (90%) out of the 10 isolates showed resistance to Anonna muricata aqueous extracts. This study reveals that the isolates of Staphylococcus aureus were significantly more susceptible to alcohol extract of  A. muricata than to cefoxitin consistently at concentration of 500-800 mg. There is a need for further studies aimed at evaluating its potentials against other isolates.

Open Access Original Research Article

Morphology, Rheology and Functional Properties of Starch from Cassava, Sweet Potato and Cocoyam

Ariwaodo Chinenye Agnes, Ezeama Chidi Felix, Nwabueze Titus Ugochukwu

Asian Journal of Biology, Page 1-13
DOI: 10.9734/AJOB/2017/34587

Aims: To produce starch from cassava variety varieties (30572, 419, and umu 37), sweet potato root (x-igbariam), cocoyam (edeuhie and NXS003). To study and compare their functional, pasting and micro-structural properties.

Study Design: Multifactor randomized complete block design (RCBD) was used for this study.  Each experiment was repeated in duplicate. Data obtained were subjected to analysis of variance (ANOVA) at the significant level of 5% (p≤.05) using SPSS 20.

Place and Duration of Study: Department of food science and technology, Michael Okpara University of Agriculture, Umudike, between May 2016 and October 2016.

Methodology: A Total of 6 (six) starch samples were produced from cassava variety varieties (30572, 419, and umu 37), sweet potato root (x-igbariam), cocoyam (edeuhie and NXS003). The starch samples were analyzed for functional, pasting and micro-structural properties.

Results: The starch from different tuber crops analysed showed different functional, pasting and micro-structural properties. At p≤.05 significant level, Pasting temperature was highest in cocoyam starch sample (ede) while cassava starch sample 419 was the lowest. Peak, trough and breakdown result was highest in sweet potato starch while peak was lowest in Cocoyam starch sample. Solubility was highest in cocoyam (Ede) and lowest in cassava sample 419. The microscopic picture of starches showed spherical shape for all granules with cocoyam starch having smooth, fine and regular circle shape. Cassava starch sample 30572 was highest in granular size while 419 recorded lowest granular size.

Conclusion: Starch from different plants and varieties significantly differ in their functional, pasting and micro-structural properties. Different starch products require different physiological properties and when starch source is rightfully selected; different starch source shows optimum functionalities in specific product.

Open Access Review Article

Plants as Expression Systems for Recombinant Proteins

Fanuel Kawaka, Alex Ngetich

Asian Journal of Biology, Page 1-8
DOI: 10.9734/AJOB/2017/34748

Plants provide a wide range of important biological molecules that are needed in research, medicine and industry. Currently, there is a growing interest in the use of plants as expression systems for the production of recombinant proteins using different host cells. The synthesis of proteins in plants is safe, economical and can be scaled up compared to the microbial and mammalian expression systems. Despite the fact that plant systems are widely recognized for producing recombinant proteins, there are certain improvements that should be addressed before the system is considered commercially viable. Such challenges include the need to identify promoters that would provide comparable yield to other systems, enhance protein stability and recovery. In this review, we describe the production of some plant based proteins, challenges and advantages of plants systems.