Browsing by Author "Makirita, Winisia E."

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Antimicrobial and Cytotoxicity Activity of Clausena anisata, Acokanthera shemperii and Olea europaea Growing in Tanzania
(European Journal of Medicinal Plants, 2016-04-21) Makirita, Winisia E.; Chauka, Leonard J.; Chacha, Musa
Aims: To evaluate antimicrobial and cytotoxicity activities of Clausena anisata, Acokanthera shemperii and Olea europaea against seven Gram negative bacteria and fungal species. Study Design: Bioassay of antimicrobial assay was done using 96-well micro-dilution method. Place and Duration of Study: School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania, from April 2014 to June 2014. Methodology: 96-well micro dilution method was used in antimicrobial assay. Extracts were loaded in the wells of the first row, followed by serial dilution and 50 μl of the bacterial suspensions (0.5 MacFarland standard turbidity) were added in each well. The first concentration which showed no bacterial growth was considered as minimum inhibition concentration. Method developed by Meyer et al 1982 was adopted in cytotoxicity activities. Results: All extracts indicated antibacterial activity on at least three to five of the tested seven bacteria and two fungi species with MIC value ranging 0.7812 - 12.5 mg/mL. The highest activity was demonstrated by Olea europaea leaf methanolic, Acokanthera shemperii stem bark and Clausena anisata twigs ethyl acetate extracts with MIC value of 0.7812 mg/mL against Pseudomonas aeruginosa while the same MIC value was exhibited by Olea europaea stem bark methanol against Proteus mirabilis. However the Olea europaea root methanolic extract inhibited the growth of Pseudomonas aeruginosa and Salmonella kisarawe with MIC value of 0.7812 mg/mL. Olea europaea leaf methanolic and stem bark methanolic which demonstrated high antimicrobial activity were non toxic against brine shrimp larvae with LC50 value of 369.8272 and 226.1566 µg/mL, while Clausena anisata twigs ethyl acetate, Acokanthera shemperii stem bark ethyl acetate and Olea europaea root methanolic extracts were toxic with LC50 value of 6.21276, 67.4179 and 92.3089 µg/mL respectively. Conclusion: This study has unveiled antimicrobial and cytotoxicity properties of Clausena anisata, Acokanthera shemperii and Olea europaea.
Development of bio-pesticide for management of spodoptera frugiperda (j. e. smith) and other lepidoptera pests of maize in Tanzania
(NM-AIST, 2020-03) Makirita, Winisia E.
This study was conducted to evaluate the infestation levels and develop management option for a Lepidoptera namely fall armyworm (Spodoptera frugiperda J. E. Smith). The survey was carried out in three regions of northern Tanzania namely; Kilimanjaro, Arusha and Manyara regions, and bioassay tests were conducted at the Hunan University of Technology and Nelson Mandela African Institution of Science and Technology. Six villages per region were surveyed, and a total of 210 maize growers were interviewed in all regions during maize growing season in 2018. A scale of 0 (no damage) to 9 (100 % damage) was used to assess severity of S. frugiperda in the study area. Performance of bio-based formulation against G. mellonella and S. frugiperda were measure by the percentage of insect mortality recorded 2 days and 9 days post-treatment for entomopathogenic nematodes and plant extracts treatments respectively. Data collected were analyzed using GenStat software 16 th edition and SPSS version 21. Results indicated that S. frugiperda incidence and severity level on maize were 66.59 % and 5.422; 52.96 % and 4.756; 52.64 % and 3.989 for Arusha, Kilimanjaro and Manyara regions respectively. The commonly applied pest management options by farmers in the study area were synthetic pesticides (86 %) and non-synthetic methods (14 %). Laboratory experiment showed that, formulations from Tephrosia vogelii and Dolichous kilimandscharius caused S. frugiperda larvae mortality of up to 70 % and 60 % respectively. Bio-based formulations from entomopathogenic nematodes (40 IJ/ml) caused G. mellonella larvae mortality of up to 100 %. On the S. frugiperda, the same nematodes concentration caused high mortality 48 h after treatment indicating that it can be used against S. frugiperda. Bio-formulation of nematodes in UV protecting ingredients caused higher larvae mortality (20 %) than the aqueous formulation (0 %) under direct sunlight for 6 h, indicating that nanoparticles protected the nematodes against UV radiation. Of the two biopesticide formulations, entomopathogenic nematodes had high performance, and thus, this study recommends the use of entomopathogenic nematodes for the management of S. frugiperda and other Lepidoptera. However, further study on their performance in different agricultural systems is needed.
Effects of Growth Conditions on the Forms of Xenorhabdus nematophila: A Symbiotic Bacterium of the Entomopathogenic Steinernema carpocapsae
(Ingenta, 2019-06) Zhang, Fengqin; Makirita, Winisia E.; Wu, Lili; Yajie, Gou; Liu, Yong; Peng, Liuliang; Chacha, Musa; Mbega, Ernest; Li, Xiaolong; He, Nongyue; Liu, Tonghua
Xenorhabdus nematophila (X . nematophila) is a mutualistic gram negative bacterium, associated with the entomopathogenic nematodes of the genus Steinernema. The nematode-bacterial complexes increase the pathogen's ability to kill a wide range of host insect in 24–48 h after infestation, due to the complex toxins produced by the primary form of the X . nematophila bacteria. Recently, the application of primary bacterial in pest control and mass production of Steinernema carpocapsae nematode is increasing. However, the association of culture conditions on bacterial growth and its effects on the symbiotic relation and pathogenicity still needs to be explored. Based on the limited information regarding the influence of culture conditions for bacterial growth, this study explored the effect of pH, temperature and culture time on primary and secondary bacterial growth, as well as physiological and biochemical parameters. Results showed that the growth and metabolism of the primary bacteria depend on the growth conditions more than the secondary bacteria. The primary bacterial form was easily and completely transformed to the secondary form after growing for 72 h, showing morphological change from rod-shaped to granular shape. The bacterial growth was directly proportional to the increase in temperature, although the temperature of 25 °C was the optimum for the primary bacteria growth. The secondary bacterium was stable under all pH growing conditions tested, but the primary bacteria did not grow at pH value of 5.166. Thus, using pH differences, secondary bacteria can be purified from the primary bacterium. Also, both forms of the X. nematophila reacted positive on glucose test, indicating high affinity to glucose substrates. Therefore, this study presents the basic growth conditions required for the symbiotic bacteria for effective production of entomopathogenic nematode (Steinernema carpocapsae), although the effect of bacterial growth conditions on both the nematode survival and productions needs to be studied further.
Sustainable Crop Protection Using Nematodes (Steinernema Spp) as Biological Control Agents
(American Scientific Publishers, 2019-06-01) Makirita, Winisia E.; Myima, Pentok; Wu, Lili; Liu, Yong; Chacha, Musa; He, Nongyue; Li, Xiaolong; Zhang, Fengqin; Liu, Tonghua
Crop productions play an important role in food production, raw material production and income generation. Crop production is challenged by pest infestation with new outbreaks every now and then, reducing yield and increasing production cost. The use of biological control agent has been cited as the potential approach in pest management due to the high performing ability with limited effects on the environment and non-targeted organisms. Entomopathogenic nematode is one of the biological control agents used for management of insect pest and it is mostly used in many developed countries with increasing application interest in developing countries. Entomopathogenic formulations from steinernema species (spp) are commercially available, although shipping and stability have been the major challenge. Recently, more than 90 spp. have been isolated from different region and this shows the possibility of having more beneficial strains of steinernema in our surroundings. Research have determined the high performance of entomopathogenic nematode against local insect, this shows the importance of isolating local stain to manage the local pest. On other hands, the different materials have been proven to enhance the pathogenic effect and stability of the nematode when incorporated together and this opens more windows in identifying potential materials for entomopathogenic nematode formulation. Despites some few available challenges of entomopathogenic nematodes applications, it is gaining more attention in agricultural and forest industry due to its broad range of activities and this serves as a potential bio control agent. It is from this view, that this review discussed the potential of Steinernema spp. in crop protection and its performance.