Asian Journal of Microbiology and Biotechnology

Microbial, Physicochemical and Sensory Quality of Freshly Extracted Apple and Cucumber Juice Subjected to Preservatives and Storage Conditions

Omorodion, Nnenna J. P., Ogbuagu, Justice O. — Thu, 25 Jan 2024 00:00:00 +0000

Fruit juices are commonly consumed for their refreshing attribute, nutritive values and health benefits. Fruit juice samples were treated with 0.5 g/ml garlic, 0.5 g/ml ginger, 0.25 g/ml mix of ginger and garlic and 0.05% (w/v) of sodium benzoate respectively where the ginger, garlic and sodium benzoate serve as natural and artificial preservatives. Their effects on the fruit juices were evaluated during 8 days of storage at 4°C and ambient temperature (28±2°C). Juice treated with sodium benzoate had the least microbial contamination while the untreated juice had the highest. The bacterial isolated from the samples were Staphylococcus sp, Bacillus sp. (Most occurring bacteria isolated), Micrococcus sp, and lactobacillus sp. The fungi isolated in the course of the study were Aspergillus sp, Rhizopus sp and Penicillium sp. (The highest occurred fungi isolated). There was a marginal decrease in pH values across treatments in stored juices with juice stored at 4°C showing the least change in pH compared to that stored at ambient temperature. The results obtained show that the preservatives exhibited an antimicrobial effect on the microbial load. The Total titratable acidity of all samples increased with time at ambient temperature and decreased at refrigerated temperature. The ascorbic acid content of both juices samples at storage temperatures decreased after the storage period due to the high sensitivity of vitamin C to oxygen, light, heat, etc. In conclusion, the findings of this study generally indicate that combination of chemical and natural preservation together with refrigeration is suitable for the preservation of fruit juice for a long time. Chemical preservatives can be recommended to be replaced with natural preservatives such as ginger and garlic, since the process is inexpensive and easy. However, preservation of fruit juice at ambient temperature for a long time should be discouraged to reduce microbial contamination.

Nutritional Properties, Antioxidant and Antimicrobial Activity of Seed and Peel Extracts of Grapefruit (Citrus paradisi) on Some Selected Clinical Organisms

Ifeoma Vivian Anyiam , Christiana Ngozi Opara , Tochi Paschaline Ezelarry — Thu, 29 Feb 2024 00:00:00 +0000

The need for new antimicrobial agent is linked with the emergence of strains that are restraint to most antibiotics and plants are safer alternative source of antimicrobials. This study aimed at determining the nutritional properties, phytochemical constituents, antioxidant and antimicrobial activity of seed and peel Citrus paradisi. The test organisms were obtained from a tertiary hospital were analyzed using conventional microbiological methods. The ethanol and aqueous extracts of C. paradisi was obtained using the rotary evaporator. Antimicrobial activity was determined using agar well diffusion method. Proximate composition of seed and peel of C. paradisi were moisture, protein, ash, fibre, lipid and carbohydrates. Qualitative phytochemical constituents revealed the presence of alkaloids, saponin, tannin and flavonoids, and Quantitative phytochemical constituents revealed 19.41 mgGallic acid equivalent/g and 8.07 mgGallic acid equivalent/g of total phenols of ethanolic and aqueous peel extracts respectively. The ethanolic extract of seed had phenolic content of 3.73 mgGAE/g. The ethanolic peel and aqueous seed extracts showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity of 35.32% and 25.32% respectively. The ethanolic seed extract of C. paradisi exhibited antimicrobial activity against all the bacterial test isolates at different concentrations. At 500mg/ml and 250mg/ml, P. aeruginosa showed the mean zone of inhibition of 18mm respectively. The largest mean zones of inhibition for S. aureus and E.coli were seen at 500mg/ml and 250mg/ml with 20mm and 27mm respectively. The ethanolic peel extract of C. paradisi exhibited antimicrobial activity at 500mg/ml against P. aeruginosa and S. aureus, with the largest zones of inhibition of 25mm and 20mm respectively. At 250mg/ml, E. coli, had the largest mean zone of inhibition of 25mm. No antimicrobial activity was observed for both ethanolic peel and seed extracts of C. paradisi against Aspergillus spp. The aqueous extract of the seed of Citrus paradisi at the different concentrations showed no antimicrobial activity against both the bacterial and fungal isolates. The aqueous extract of the peel had antimicrobial effect on P. aeruginosa at 125mg/ml with mean zone of inhibition of 15mm. At 500mg/ml S. aureus and E. coli exhibited zones of inhibtion of 15mm and 20mm respectively. No zone of inhibition was observed with Aspergillus spp. This investigation indicates the peel of C. paradisi has medicinal activity and holds the potential as therapeutic agent for treating microbial infections.

Reaction of Gidami Coffee Collections against the Major Diseases

Zenebe Wubshet, Gabisa Gidisa , Hailu Negesa, Kifle Belachew — Sat, 16 Mar 2024 00:00:00 +0000

Ethiopia's largest export commodity is coffee arabica, one of the most significant goods that significantly contribute to the national economy. However, diseases including coffee berry, coffee leaf rust, and coffee wilt have been significantly reducing its yield. In order to assess Gidami coffee arabica accessions’ reaction to serious fungal infections, this study was started. The total of 100 genotypes was evaluated under Gera and Haru field situations for these major diseases. Whereas, 92 accessions with two checks were tested under greenhouse condition for coffee wilt. The results showed a highly significant variation (p<0.001) among genotypes in both conditions with 0–51%, 4–36%, and 0–100% disease severity ranges respectively. Except the four accessions namely G67/13, G71/13, G54/13, and G66/13, most of them showed susceptible reactions to CBD under Gera conditions. As well, 36 and 12 coffee accessions revealed <10% CLR reactivity at Haru and Gera conditions respectively. But none of the accessions had resistance levels higher than the two checks (Challa and 8136) at either of the locations. In other word, Gera had much greater levels of CBD and CLR pressure than Haru. On the other hand, only two accessions, G57 and G20, showed 100% CWD survival rate in greenhouse environments. This study showed how plant genetics and environmental variables affect diseases development and demonstrated that the response of Gidami coffee accessions to the major coffee diseases highly influenced by geographical and genetic variables. Therefore, continual and massive genotype screening across the locations must be taken into account in order to get resistance genotypes as the best disease mitigation to overcome the coffee diseases problem.

Ecological Significance of Dynamism of Physiologic Variance on Properties of Palm Oil Mill Effluents

Thu, 04 Apr 2024 00:00:00 +0000

Properties a given waste is essential for rationale comprehension of plausible way(s) for its remediation. In the present study, POME from oil milling centre at Anambra state showed high heterotrophic activity of microorganisms. Total viable counts of the organisms isolated from the waste water were 5.4 x 10³ CFU/ml and 4.4 x 10³ CFU/ml at day 0 and day 7 of the incubation respectively. These observations showed a significant variation from the control experiment at these recorded days of incubations which shows total viable cell counts (TVC) of 4.6 x 10³ and 2.9 x 10⁴ CFU/ml respectively. Total coliform counts (TCC) of the organisms isolated from the dairy waste water were 1.3 x 10³ and 1.8 x 10³ CFU/ml for the day 0 and day 7 incubation periods respectively while the TCC from the control experiment were: 8.0 x 10² and 3.2 x 10² CFU/ml for day 0 and day 7 incubation periods respectively. POME sample from Awka, Anambra state was subjected to various physicochemical profiling and was further optimized at different conditions to exert various variability. Biochemical oxygen demand (BOD₅) is one of the important physical parameter widely used in assessment of quality of aqueous surroundings. Physicochemical properties of waste water from the milling centre showed the following: pH (5.0), temperature (41^oC), conductivity (610); water dissolved minerals such as Cl^-, K⁺, PO₃, Mg2⁺, Ca²⁺ were all determined. Initial dissolved oxygen concentration (mg/l) of the waste water was determined using a probe connected to a meter with initial value of 39.4 mg/l. Biochemical oxygen demand (BOD₅) was determined after five incubation days at room temperature in separate bottles optimized at varying pH of 4.0-9.0 in a range of 1.0 units. BOD₅ decreases with increased pH values in all the tested samples incubated for 5 days. pH 5.0 gave a significant reduction of the oxygen exertion (1400 mg/ml) while pH 4.0, 6.0, 7.0 showed an oxygen exertion (BOD₅) of 1978, 2778, and 2965 mg/ml respectively. Samples incubated at 8.0 and 9.0 showed oxygen exertion of 2945 and 2899 mg/ml respectively. Other contents of the dairy waste water such as total organic carbon (TOC), total organic matter contents (TOM) were all determined respectively. Samples was also collected from mapped area 0.5 km away from the waste water reservoir and used as the reference standard. Proceeding results from the present research study showed the compromised statues of our aquatic environment and also in a wider look gave a great insight of effective modalities in water treatment; as increasing population of myriads of processing industries in our country today pose great challenge to the competence of our aquatic body.

Effects of Climate Change on the Spread and Severity of Potato Virus Y: An In-depth Examination

Narendra Kumar Ahirwar, Jitendra Singh Pachaya — Tue, 26 Mar 2024 00:00:00 +0000

Potatoes are a cornerstone of global agriculture and a fundamental component of diets worldwide, with plant viruses accounting for nearly half of the emerging crop epidemics. Among these, Potato Virus Y (PVY) poses a formidable challenge to potato farming, leading to significant economic repercussions and threats to food security. Understanding the influence of climate on PVY is pivotal in tackling this viral menace. Climatic conditions, including temperature, precipitation, and humidity, play a key role in the behavior of aphids, the primary vectors of PVY, thereby impacting the disease's prevalence in potato fields. With climate change modifying these key weather variables, there's a looming risk of enhanced PVY spread and a shift in its geographical presence. Recognizing and adapting to these climate-induced changes is vital for formulating effective strategies and sustainable practices to counter PVY's effects, safeguarding potato crops from this major viral threat. This analysis delves into the complex dynamics between climate change and PVY, focusing on how changes in weather patterns influence the virus's behavior and impact, with the aim of enhancing our preparedness and response to this agricultural challenge.