Open Access Original Research Article

Mixotrophic Co-Cultivation of Chlorella lewinii LC172265 and Kluyveromyces marxianus NCYC2791 for Efficient Production of Biomass under Static Condition

O. J. Chioke, C. N. Ogbonna

Asian Journal of Biotechnology and Genetic Engineering, Page 1-9

Background: Microalgae and yeast biomass are sources of many useful metabolites such as proteins, lipids, antioxidants, vitamins and a host of pharmaceuticals. However, efficient production of microalgae biomass requires constant supply of carbon dioxide and removal of photosynthetically generated oxygen. On the other hand, production of yeast biomass requires adequate supply of organic carbon and constant supply of oxygen. It is therefore expected that co-culture of the two microorganisms can be achieved without aeration since the culture will be oxygenated by the oxygen released by the microalgae and carbon dioxide will be supplied by yeast fermentation.

Aim: In the present study, the feasibility of co-cultivation of Chlorella lewinii and Kluyveromyces marxianus for efficient production of biomass without aeration was investigated.

Methods: BG11 medium was used as the basic medium and the effects of nitrogen source on the growth of the cells in monocultures were first investigated. Subsequently, the effects of inoculum ratios and glucose concentrations on the growth of Chlorella lewinii, Kluyveromyces marxianus and total biomass concentrations in co-cultures were investigated.

Results: The results showed that urea was the best nitrogen source for the growth of the two strains. In their monocultures, the maximum concentrations of C. lewinii and K. marxianus were1.62 x 109cells/ml and 7.719 x108cells/ml, respectively. The optimum inoculum ratio of K. marxianus to C. lewinii was 1:60 and a total cell concentration of 8.25 x109cells /ml was achieved. Although as the initial glucose concentration was increased from 5 g/L to 20 g/L, the total biomass concentration increased, the growth of K. marxianus increased while that of C. levinii decreased. The highest total biomass yield per gram of glucose was obtained with an initial glucose concentration of 5 g/L.

Conclusion: Co-cultures of C. lewinii and K. marxianus is an effective method for production of their biomass without external supply of oxygen and carbon dioxide.

Open Access Original Research Article

Evaluating the Assault Caused by Nauclea latifolia on the Biochemical Parameters of Wistar Rats Following Testicular Tissue Damage

Eno-Obong I. Bassey, Jessie I. Ndem, Kingsley A. Okon, Gabriel D. Edem

Asian Journal of Biotechnology and Genetic Engineering, Page 10-16

Background: The use of herbal products is very common among rural dwellers, although these products posses prophylactic, therapeutic and curative capacities. Unguarded doses most times often result in cellular and tissue damage in the body. This study was undertaken to evaluate the assault caused by Nauclea latifolia on lactate dehydrogenase, superoxide dismutase and DNA damage assay in Wistar rats following testicular tissue damage.

Methods: Forty (40) male Wistar rats divided into eight (8) groups were used for this investigation (n=5). The animals were administered with 3mg of alcohol/kg b.w alone, 5 mg of testosterone/kg b.w, 500 mg of ethanolic leaf extract of Nauclea latifolia/kg b.w, 1000 mg of ethanolic leaf extract of Nauclea latifolia/kg b.w, 1500 mg of ethanolic leaf extract of Nauclea latifolia/kg b.w, 3 mg of alcohol/kg b.w and 500 mg of of ethanolic leaf extract of Nauclea latifolia/kg b.w, 5mg of testosterone and 500 mg of ethanolic leaf extract of Nauclea latifolia/kg b.w and the control received 15 % tween 80 (10 ml of tween 80/kg b.w ) respectively. The experiment lasted for 21 days.

Results: Ethanolic leaf extract of Nauclea latifolia at doses of 500, 1000 and 1500 mg/kg b.w of rats significantly increased DNA damage and lactate dehydrogenase.

Conclusion:  Increased in these biochemical parameters signify increased tissue damage.

Open Access Original Research Article

Optimization Studies on Cellulase Production by Aspergillus niger and Aspergillus fumigatus

Ogbonna Abigail Ify, Ogbonna Ugoy Sonia Amarachi, Onyimba Isaac Amechi, Ugwu Eugene Ifeanyi, Njoku Andrew Ikechukwu, M. Madu Josephine, Ogbonna Chike Innocent Chuks, Otafu Esther Ehi

Asian Journal of Biotechnology and Genetic Engineering, Page 17-26

Aim: In this study, two fungal species, Aspergillus niger and Aspergillus fumigatus were screened and optimized for their abilities to degrade cellulose using filter paper and Carboxymethylcellulose (CMC) as substrates.

Materials and Methods:  Aspergillus niger and A. fumigatus procured from the Applied Microbiology Unit of Department of Plant Science and Biotechnology, University of Jos were screened using Whatman No. 1 filter paper and Carboxymethylcellulose as substrates in Petri plates. The fungal species abilities to produce cellulase at varying optimization parameters such as incubation periods (5 days), different incubation temperatures (25-500C), different pH(3-9) and different substrate concentration (0.25-2%) using Submerged Fermentation (SmF) were also studied.

Results: The plate assay showed that the two species produced cellulases. The highest cellulolytic activity was shown by A. niger (23±3.22 mm) as it had larger zones of clearance compared to A. fumigatus (13±3.06 mm). However, the organisms grown on filter paper agar showed better hydrolysis compared to the growth on CMC agar. For the Submerged Fermentation (SmF), enzyme activity increased for the first 98 hours of incubation on filter paper recording 2.62 IU/ml for A. niger and 2.45 IU/ml for A. fumigatus after 48 h and then there was decrease in enzyme activity. For the CMC, the highest enzyme activity was observed at 48 h recording 1.76 U/ml and 1.37 IU/ml for A. niger and A. fumigatus respectively. Maximum enzyme production was observed at incubation temperature of 30 0C for A. niger and A. fumigatus recording 1.05 IU/ml and 1.10 IU/ml on filter paper. Enzyme activity was found to be highest at pH 6 with A. niger and A. fumigatus recording 2.27 IU/ml and 2.03 IU/ml respectively on CMC broth. The 2% substrate concentration gave the highest enzyme activity of 0.58IU/ml and 0.54IU/ml for A. niger and A. fumigatus respectively. The increase was linear, the higher the concentration of the substrate, the higher the enzyme activity.

Conclusion: Aspergillus  niger and A. fumigatus have demonstrated potential of synthesizing hydrolytic cellulolytic enzymes and could be employed in the degradation of lignocellulosic wastes. These enzymes could find applications in different industries.

Open Access Original Research Article

Bioassay Toxicity Assessment of Remazol Brilliant Blue and Aniline Purple Textile Dyes Contaminated Water Using Zea mays and Sorghum bicolor

Solomon Peter Wante, Nafisah Saeed Saleh, Habiba Usman Aliyu, Wasa Alibe Ahmed, Kwaya Vawanje Bitrus, Mamoon Asiya

Asian Journal of Biotechnology and Genetic Engineering, Page 27-34

The bioassay evaluation of the toxic textile dyes contaminated water has become highly essential due to indiscriminate discharge of wastewater from the local textile dyes factories in Nigeria and also around the world. Textile dyes wastewater has a reasonable amount of organic and inorganic substances, in many cases high load of heavy metals. In this study, the Remazol brilliant blue (RBB) and Aniline purple (AP) textile dyes contaminated water recorded high biochemical oxygen demand (BOD) and chemical oxygen demand (COD) values above the standard requirement of wastewater discharge. Germination percentage of Zea mays and Sorghum bicolor seeds decreases with increasing concentration of Remazol brilliant blue and Aniline purple textile dyes water. Sorghum bicolor seeds have shown to be more sensitive to the different types and various concentrations of textile dyes compared to Zea mays. About 90 and 95% of Sorghum bicolor seeds did not germinate in the different types of textile dyes at various concentrations. Lack of further development of germinated seeds to a distinct root and shoot was also observed in Sorghum bicolor compared with the Zea mays germinated seeds.

Open Access Review Article

A Comprehensive Review on Breeding Technologies and Selection Methods of Self-pollinated and Cross-Pollinated Crops

Adil Hussain, Kamran Arshad, Jareer Abdullah, Ayesha Aslam, Aqsa Azam, Muhammad Bilal, Muhammad Asad, Ameer Hamza, Muhammad Abdullah

Asian Journal of Biotechnology and Genetic Engineering, Page 35-47

The basis of crop improvement is the existence of genetic variability in plant material. A breeder exploits it in several different ways to create new crops varieties which are capable of outperforming their ancestors in the expression of various economic characters like yield, quality, resistance to diseases, and tolerance towards drought conditions. Breeders obtain their purpose by using different breeding technologies and selection methods. This review categorizes all the breeding technologies into two main portions of selection methods of self-pollinated crops and that of cross-pollinated crops. The principal methods by which new varieties of self-pollinated crops originate are selection and hybridization. Self-pollinated crops can also be developed by pure-line selection methods. Dirk and Penjamo-62 of wheat, IR-6 of rice, and Beechar of barley are the cultivar introductions in Pakistan. Using these methods, most of our crop varieties like wheat, cotton, sugarcane, maize, clover, and several other crops can be originated. The second portion of this review explains breeding methods of cross-pollinated crops. The methods used in the breeding of cross-pollinated crops or crops such as cotton and sorghum which have both self and cross-pollination are not as clearly defined as the methods used in the breeding of self-pollinated crops. In addition, these methods tend to vary with the particular crop with which the breeder is working. Principal methods by which varieties of cross-pollinated crops can be originated by selection and hybridization. The selection method for cross-pollinated crops consists of mass selection, pure line selection, progeny selection, line breeding, and recurrent selection methods. While hybridization includes intervarietal and interspecific crossing and utilization of hybrid vigors. The whole concept gives an amazing figure to the new crop researchers in modern breeding technologies and selection methods.