Open Access Original Research Article

Production of Bioethanol from Wild Cassava Manihot glaziovii through Various Combinations of Hydrolysis and Fermentation in Stirred Tank Bioreactors

Anselm P. Moshi, Ken. M. M. Hosea, Emrode Elisante, Anthony Manoni Mshandete, Ivo Achu Nges

Biotechnology Journal International, Page 123-139
DOI: 10.9734/BBJ/2015/13981

Production of Bioethanol from Wild Cassava Manihot glaziovii through Various Combinations

of Hydrolysis and Fermentation in Stirred

Tank Bioreactors

Aim of the Study: The aim of this study was to evaluate three ethanol fermentation approaches namely (I) separate hydrolysis and common fermentation (II) separate hydrolysis and fermentation and (III) simultaneous saccharification and fermentation in stirred tank reactors using inedible wild cassava as feedstock.

Study Design: Tubers of wild cassava (Manihot glaziovii) were obtained from two districts in Tanzania. Fermentation of hydrolysate and partially liquefied cassava flour was performed in stirred tank reactors.  

Methodology: Feedstock composition analysis for structural carbohydrate was performed using acid hydrolysis and high pressure liquid chromatography technique. Analysis of total nitrogen was done by Kjeldahl acid digestion technique, total cyanide was determined using linamarase loaded picrate paper whereas macro-and micronutrients were analysed by inductively coupled plasma atomic emission spectrometry. Thermostable α-amylase and glucoamylase were used to partially hydrolyze the cassava flour to fermentable sugars prior to yeast fermentation. The hydrolysis (liquefaction) was performed at 90°C, 1h followed by saccharification using glucoamylase at 60°C, 2h for approaches I and II. For approach III, liquefaction was performed at 90°C, 1h followed by direct saccharification and fermentation. Fermentation of hydrolysate and partially liquefied starch from wild cassava was done in stirred tank reactors at 30±2°C using baker’s yeast.

Place and Duration of Study: Department of Biotechnology, Lund University from January to June 2014.

Results: The wild cassava (M. glaziovii) tubers possessed comparable physical dimensions to the domesticated cassava, however they displayed higher average flesh proportion (76 to 79%) compared to the domesticated cassava (74%). Compositional analysis disclosed that the wild cassava possessed interesting properties for bioethanol production such as dry matter of up to 89% w/w, degradable carbohydrate up to 90% (dry weight basis), total kjeldahal nitrogen 0.8-1.6% w/w and satisfactory concentration of macro-and micronutrients. Amongst the three fermentation approaches, high ethanol titre of 10-11% (v/v) at high conversion efficiency of 97.6% was achieved for separate hydrolysis and fermentation and simultaneous saccharification and fermentation, whereas low ethanol titre (4.2% v/v) at efficiency of 39% was achieved for separate hydrolysis and common fermentation. Volumetric productivities for the three approaches; ‘separate hydrolysis and common fermentation’, ‘separate hydrolysis and fermentation’, and ‘simultaneous saccharification and fermentation’ were 2.0, 5.5 and 6.5 respectively.

Conclusion: The results obtained in the present study demonstrated that wild cassava has a high starch content, contain balanced nutrients required for efficient bioethanol production and that simultaneous saccharification and fermentation is the best approach for bioconversion of the wild cassava to bioethanol using stirred tank reactors.


Open Access Original Research Article

Fatty Acid Composition and Physicochemical Properties of Four Varieties of Citrullus lanatus Seed Oils Cultivated in Côte d’Ivoire

Anne Marie Niangoran N’guetta, Yolande Dogoré Digbeu, Siaka Binaté, Jean Parfait Eugène N’guessan Kouadio, Soumaila Dabonné, Edmond Ahipo Dué

Biotechnology Journal International, Page 140-147
DOI: 10.9734/BBJ/2015/12371

Fatty Acid Composition and Physicochemical Properties of Four Varieties of Citrullus lanatus Seed Oils Cultivated in Côte d’Ivoire

In this study, the physicochemical properties and fatty acids composition of four varieties of Citrullus lanatus seed oils cultivated in Côte d’Ivoire were investigated. There was one variety (Bebu cultivar) with oval flat seeds and thick edges (COS), and three varieties (wlêwlê cultivars) with flat seeds disentangled and sharp extremity of various size (big seed (CBS), average seed (CAS) and small seed (CSS)). The pH at 30ºC was ranged from 5.85±0.003-6.03±0.001. The results for density (g/ml), refractive index, unsaponifiable matter (% of oil) and impurity (%) were 0.876±0.005-0.924±0.001; 1.4595±0.004-1.4739±0.001; 0.89±0.450-2.07±0.160; 0.05±0.002-0.1±0.001; respectively. The free fatty acid (%), acid value (mgKOH/g oil), peroxide index (meq O2/kg oil), saponification value (mgKOH/g oil), iodine value (mg of g I2/100 g oil), Total polyphénolics content (mg gallic acid/kg oil) values of the oils were obtained in the range; 0.80±0.050-2.03±0.010; 6.03±0.350-7.93±0.100; 10.93±0.470-13.80±0.100; 228.43±0.040-244.76±0.010; 84.07±11.250-93.38±1.090; 0.125±0.050-0.291±0.010; respectively. The most abundant fatty acid detected in the four oils was oleic acid ranged from 46.56-59.97. This acid constituted with the aldaic acid, the monounsaturated fatty acids in these oils and accounted for 64.82-73.07. This study showed the presence of others main saturated fatty acids as stearic acid and palmitic acid. The properties of these oils were quite comparable to those of previously  reported cucurbitaceaes seeds oils, suggesting their potential use as good table and cooking oils. With a high yield of oil and physicochemical characteristics similar to those of the other commercial edible oils, the Citrullus lanatus seed oil can be considered as a new and valuable source of edible oil. This study also showed potential for Citrullus lanatus seeds oils to ave relatively high oxidative stability that would be suitable for food and industrial applications.

Open Access Original Research Article

Identification of a Biochemical Indicator in Plants for Heavy Metal Contamination

Sonali Hazra Das, Mahasweta Paul, Shankha Ghosh Dastidar, Tulika Das, Srabanti Basu

Biotechnology Journal International, Page 148-155
DOI: 10.9734/BBJ/2015/14303

Aims: To identify a biochemical parameter in a plant(s) that can serve as an indicator of heavy metal pollution.

Study Design: Design of the study includes collection of plant samples from a contaminated site and a rural site and to check their biochemical parameters related to oxidative stress. Based on the experimental findings, attempts were made to identify a parameter that can serve as an indicator of heavy metal contamination.

Place and Duration of Study: The study was conducted in Department of Biotechnology, Heritage Institute of Technology, India, during the period from August 2013-June 2014.

Methodology: Plant samples were collected from East Calcutta Wetlands (metal contaminated site) and Binogram, a village 90 Km away from Kolkata (control site). The samples were checked for the following parameters: non-protein thiol, ascorbic acid, superoxide dismutase (SOD), lipid peroxidation. This was followed by a statistical analysis. 

Results: Non-protein thiol content was found to be less in the Ipomoea, Hygrophila and cabbage samples collected from ECW. The values were 65-75% of the village samples. Cauliflower leaves did not show any alteration in the parameter. Ascorbic acid was altered significantly in cabbage and Hygrophila. Activity of SOD decreased in all samples. Lipid peroxidation increased in all samples except Ipomoea. Of the biochemical parameters tested, maximum alteration was found with non-protein thiol, in which glutathione (GSH) is the major constituent. Of the vegetables studied, cabbage showed an alteration in all biochemical parameters.

Conclusion: GSH has the potential for being used as an indicator of heavy metal pollution. Cabbage can be used as a model vegetable for testing the biochemical parameters. The method will be helpful in identification of a contaminated site before estimation of heavy metals.

Open Access Original Research Article

Sequence Homology Studies of Phospholipase A2-like Gene from Bloodstream form of Trypanosoma brucei

Ishaya Y. Longdet, Hajiya M. Inuwa, Isma’il A. Umar, Andrew J. Nok

Biotechnology Journal International, Page 156-165
DOI: 10.9734/BBJ/2015/13971

Aim: This work focused on the sequence homology studies of the enzyme, phospholipase A2  (PLA2), in Trypanosoma brucei  obtained from the blood of bull  in Federe, Plateau State, Nigeria, West Africa

Place and Duration of Study: Department of Biochemistry, University of Jos, Nigeria; Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria, Department of Biotechnology, NVRI, Vom, Nigeria; between June 2009 and September 2011.

Methodology: T. brucei grown in rats were harvested and separated using diethyl amino ethyl (DEAE) cellulose chromatography. From the parasites’ genomic DNA the PLA2-like gene was amplified using consensus primers.  The amplicon was cloned unto pMal-2cE vector and confirmed using direct PCR and restriction enzyme analyses. The PLA2 gene and translated protein sequences were studied using National Center for Biotechnology Information (NCBI) Conserved Domain Search Tool and Conserved Domain Architectural Retrieval Tool

Results: Analyses of the 1344bp gene sequence using bioinformatics tools showed that it is very closely related to PLA2 sequences of T. brucei (TREU 927) and T. b. gambiense. Motifs that are unique to PLA2 (FSHGL) and lipases (GHSFG) were found to be present in the query sequence. The domains present in the studied sequence agreed closely with those of the human platelet activating factor acetyl hydrolase (PAF-AH). There was also a good sequence resemblance with PLA2s from T. cruzi, Metarhizium amisop, Metarphizium acridu and PAF-AH in terms of architecture.

Conclusion: The PLA2-like gene isolated from the blood stream form of Trypanosoma brucei and studied was found to posses the domains and motifs unique to PLA2s and lipases and so homology was established among the proteins.

Open Access Review Article

Starch Phosphorylase: An Overview of Biochemical Characterization, Immobilization and Peptide Mapping

Ritu Jain, Sarika Garg, Anil Kumar

Biotechnology Journal International, Page 103-122
DOI: 10.9734/BBJ/2015/14522

Starch Phosphorylase: An Overview of Biochemical Characterization, Immobilization and

Peptide Mapping

Starch phosphorylase (EC is the key enzyme which catalyzes the reversible conversion of starch and inorganic phosphate into glucose-1-phosphate (G-1-P) and has been reported in many higher plants. It can be exploited for industrial purposes for tailoring starch and for the synthesis of biopolymers which may be useful in food industry and are also of clinical importance. Starch in the form of insoluble granules accumulates in chloroplasts as the primary product of photosynthesis. Multiple forms of the enzyme have been reported in different plant tissues which have been predicted to have different roles in starch metabolism. Here, various biochemical properties have been reviewed. Various techniques for enzyme immobilization have been discussed. Besides, reports on immobilization of starch phosphorylase from different sources and on different solid matrices have also been reviewed. Peptide mapping reports of various proteins have also been assessed in this review.