Biotechnology Journal International

Virulence and Molecular Detection of Cassava Mosaic and Brown Streak Virus Genes on Elite Mutant Cassava Lines

Lydia Chepkoech Kimno — 2023-10-03

Unavailability of germplasm with Cassava Brown Streak Disease (CBSD) and Cassava Mosaic Disease (CMD) tolerance genes remains the main bottleneck towards management of the two diseases in tropic and sub-tropic regions in Africa. We assessed the pathogenicity of two viruses and established the presence of genes linked to CBSD and CMD among some elite cassava lines using field techniques and PCR methods. The screen-house experiment was arranged in split plot in completely randomized block design replicated thrice. Severity data was done on a scale of 1 - 5 at an interval of 14 days post inoculation. Symptomatic fresh leaves were used in the extraction of genomic deoxyribonucleic acid and amplification done using markers linked to African cassava mosaic virus (ACMV), separated bands scored as present (+) or absent (-) and visualized under UV trans-illuminator. Virulence and pathogenicity results showed higher tolerance to CBSD and CMD under single inoculation. In contrast, dual inoculation synergistically increased severity expression leading defoliation at early stages of growth. DNA amplification found no CBSD and CMD alleles in CAS1. However, some traces of the alleles were amplified on CAS2, CAS3, KME3 and KME4. Mutant cassava lines exhibited low severity compared to parental lines which were genetically different in terms of viral genes detected by the ACMV linked markers.

Precipitation Using Organic Solvents for Purifying Lipase from Preussia africana

Eric E. A. Ferreira — 2023-10-14

Aims: The present study aimed to purify a new lipase from the endophytic fungus Preussia africana (P. africana).

Study Design: Lipases were produced through fermentation and precipitation using different organic solvents and characterized at optimal temperature and pH conditions.

Place and Duration of Study: Assays were carried out at the Laboratory of Bioprocess at the Federal University of Alfenas between January and August, 2023.

Methodology: Enzymes were produced via submerged fermentation. After fermentation, the broth was filtered and lyophilized so that enzymes were concentrated. Organic solvents (methanol, ethanol, isopropanol and acetone) were used at 10 and 25°C for lipase precipitation. A second precipitation step was investigated in a supernatant: solvent ration ranging from 1:3 to 1:2 (v/v) and temperatures between 10°C and 25°C. Optimal temperature and pH conditions for the hydrolytic activity of precipitated lipase were also found.

Results: Acetone and isopropanol were more efficient in precipitating lipase while maintaining its catalytic activity, as specific activities of 211.34 ± 0.05 and 179.50 ± 0.08 U/mg were achieved, respectively. For the second precipitation step, acetone in a supernatant: solvent ratio of 1:2 (v/v) at 10°C achieved optimal performance, as purification factor of 1.89 ± 0.01 and recovered activity of 93.45% were found. Maximum hydrolytic activity of 72.80 ± 1.29 U/mL was observed using olive oil as substrate at pH between 7 and 8 and 37°C.

Conclusion: The use of acetone at 10°C in two precipitation steps proved to be a more robust strategy for P. africana lipase precipitation in the purification process.

Prevalence of Enterobacteria Species in Different Hospital Wards of a Tertiary Health Facility in Imo State, Nigeria

Emmanuel Chimela Ibe — 2023-10-14

Aim: to assess the prevalence of Enterobacteria species in different hospital wards in a healthcare outfit in Imo State, Nigeria.

Study Design: The randomized complete block sampling design was adopted for the study.

Place and Duration of the Study: Sample: Imo State University Teaching Hospital, Federal Medical Centre, Owerri, Aboh-Mbaise General Hospital, and Imo State Specialist Hospital. Between May to October, 2021.

Methodology: Using Cochran formula, a total of 360 samples were collected for the study from bedpan, ward floor, bed cover, and staff gloves, at maternity, ICU, and surgical theatre wards. Sample were collected by swabbing the surfaces using sterile swab sticks soaked in saline water. Following standard microbiological procedures, which include bacteria culturing in MacConkey agar to select for Enterobacteria, subculturing on salmonella-shigella agar and cetrimide agar to obtain pure cultures of specific bacteria species; the samples were subjected to morphological, and biochemical characterization. The prevalence was determined and compared for significance (P = .05).

Results: The investigation showed the presence of Escherichia coli (29%), Pseudomonas aeruginosa (26.84%), Klebsiella pneumoniae (25.11%), and Shigella species (19.05%), in all the outfits investigated, with their percentage occurrences. The wards floor showed the highest number of Enterobacteria species (38.96%) while the staff gloves showed the least (9.96%). Based on the wards investigated, surgical theatre showed the highest prevalence rate (20.25±6.55) and ICU had the least prevalence rate (17.75±5.63). The prevalence pattern of Enterobacteria species were significantly (P = .01) dependent on the healthcare outfits. The prevalence pattern between the hospital wards was not significant (P = .59) and there was no significant interaction between the hospital wards and hospital equipment (P = .84).

Conclusion: Enterobacteria species was present in the healthcare outfits (bed pan, ward floor, bed cover and staff gloves). Its prevalence is dependent on these hospital outfits but not influenced by the wards or the interaction between wards and hospital outfits.

Effects of Different Temperature Treatments on Seed Germination and Seedling Growth of Rorippa sylvestris

Hai ling Yan — 2023-10-25

Temperature is one of the important conditions for plant growth, and an important factor affecting the establishment and spread of invasive plants. In this study, the northern perennial invasive plant (Rorippa sylvestris) was taken as an example. By comparing the seed germination rate, germination potential, germination index and vigor index, the total number of leaves, root length, root length, vigor index, leaves of seedings, seedling biomass and root- shoot ratio under different temperature treatments (15, 20, 25, 30, 35, 40℃), the subordinate function was used to compare the temperature tolerance of R. sylvestris in seed germination. sylvestris in seed germination and seedling growth. To study the response and tolerance of seed germination and seedling growth of invasive R. sylvestris to different temperatures, the subordinate function was used to compare the temperature tolerance of R. sylvestris in seed germination and seedling growth. The results showed that high temperature promoted seed germination of R. sylvestris and limited radicle growth, and it had the most tolerance at different temperatures. The results showed that high temperature promoted seed germination of R. sylvestris and limited radicle growth, and it had the strongest tolerance at 35℃. Lower temperature was more beneficial to material accumulation of seedlings, and the tolerance of R. sylvestris was more favorable. The results provide theoretical basis for revealing the diffusion and invasion mechanism of R. sylvestris.

Anthelmintic Potential of Vernonia amygdalina on Toxocara canis in Domesticated Dogs

Adams, Eka — 2023-11-06

Toxocariasis is a worldwide zoonotic parasitic infection and one route of preventing the disease in dogs and subsequent transmission to humans, especially children, is through treatment with anthelmintic. A study aimed at assessing the anthelmintic efficacy of Vernonia amygdalina leaves extract on Toxocara canis in domesticated dogs was carried out where the proximate and phytochemical components of the leaf extract were determined using the standard method and Gas Chromatography-Mass Spectrometry, the anthelmintic efficacy was assessed in vitro and in vivo respectively. The study revealed that this plant contained alkaloids, saponins, tannins, glycosides, flavonoids, terpenoids, phenol and steroids. Lethal concentration (LC50) of 14.83ml/mg at 12 hours and a percentage egg reduction of 84% after 2 weeks was recorded, which revealed that the plant leaves have anthelmintic potential and this could be attributed to the presence of flavonoids which are associated with the treatment of gastric infections and also n-Hexadecanoic acid which accounts for it anthelmintic (nematicidal) effect, alongside Octadecanoic acid which is an anti-inflammatory compound.

Genetic Diversity and Phylogenetic Relationships among Jatropha curcas L. Genotypes from Eastern India

Sanjay Singh — 2023-11-20

Genetic diversity and relationships among 31 genotypes collected from wide geographical range in eastern India was studied employing Random Amplified Polymorphic DNA (RAPD) markers. 19 markers (identified out of 25) produced 139 band in total. Off these 139 bands, 131 bands were polymorphic exhibiting a high polymorphism of 94.24%. Similarity indices estimated on the basis of RAPD primers ranged widely from 0.44 to 0.83 which suggests that these accessions represent genetically diverse population possibly due to predominance of cross pollination and seed source variability. Genotyping data obtained for RAPD primer across collected accessions were used to generate the UPGMA - based phylogenetic tree which shows two major clusters. The cluster I consisted of 16 genotypes from two states Jharkhand and Odisha (Chotanagpur and Eastern plateau region) while 15 accessions from West Bengal and Bihar (Indo Gangetic plains region) were grouped together in the Cluster II. This clear alignment of accessions into two different clusters as per geographical regions was probably due to different growing conditions in two clusters.