Nigerian Journal of Biotechnology

Alkaline Protease Production by Immobilized Klebsiella aerogenes Cells from Dairy Effluent Sludge

M.B. Osho — 2023-02-15

This study investigated the screening of alkaline protease microorganism from diary effluent sludge and identified by 16S ribosomal RNA nucleotide sequence as Klebsiella aerogenes with accession number MF156964.1 and maximum identity 95.45%. The cells were immobilized with coconut pod husks and optimization studies such as the effects of particle sizes, pH, temperature, agitation speed, and incubation time were determined. Out of twenty three microorganisms screened, three were potential protease producers. K. aerogenes gave the highest zone of hydrolysis (35 mm) on the skimmed milk agar plate. The particle size (0.075 mm2) of the immobilization agent gave the highest enzyme activity 176.83 U/mL. The optimum incubation time for the production of protease was 48 h with enzyme activity 143.054 U/mL which further declined. The optimum pH of the protease was pH 9.0 with activity 209.61 U/mL which made it alkaline. The agitation speed 150 rpm resulted in a protease activity 175.83 U/mL and reduced by 56.5% at 250 rpm. The optimal temperature 35 ºC was 183.78 U/mL. This study also confirmed the stability and reusability of the immobilized cells using the coconut pod husks matrix by maintaining from 100% to 76.2% up to six times recycle. Conclusively, the study established the efficiency of low cost, readily available matrix and reusability potentials of coconut pod husks for cells immobilization technology through entrapment at optimal conditions for protease production.

Polyploidy and its relevance in crop improvement

E.A. Omere — 2023-02-15

Many areas of research in crop production have been geared towards crop improvement and increased yield. Crop improvement include but not restricted to; plant introduction and acclimatization, domestication, ploidy manipulation (polyploidization), recombinant DNA technology, crossing for superior selection (cultivar development), molecular genetics, etc. Polyploidy is a condition where the genome of an organism has more than the usual number of complete sets of chromosomes and the product of this phenomenon is called a Polyploid. Polyploidy occurs naturally, and can be induced chemically using antimitotic agents or physically using protoplast fusion and temperature shock. It is mostly artificially induced through a process called polyploidization. Polyploids are more advantageous in important plant attributes than the regular diploid. Relative success has been reported in the application of polyploidization for crop improvement which resulted chiefly in increased amount of beneficial secondary metabolites (phytochemicals), larger stomata and leaves,improved adaptation to stress and unfavourable conditions, to mention but a few. Therefore, it is imperative to state that polyploidy is an area of research that has been and will continually be deployed in crop improvement .

Impact of Solid Waste on Soil Bacterial and the Municipal Waste Management in Some Communities of Lagos Island

J.M. Yakubu — 2023-02-15

The effects of solid waste on soil and soil sentinels cannot be over emphasized. On the other hand, managing municipal waste has a serious challenge. This study focused on the impact of solid waste on soil bacteria and the municipal waste management in some communities of Lagos Island which are Dolphin and Adeola Odeku Village. This study aimed at examining the present municipal waste management practices in Lagos Island and how they can be improved upon. Random sampling was used to administer 100 questionnaires to households while the different heavy metal concentrations in the soil samples were determined using Buck 200 Atomic Absorption Spectrophotometer (AAS). The wastes were mainly composed of food wastes, plastics/pet bottles and nylon. Although the majority of the respondents (65%) had waste bins/bags assigned to their houses, about 73.86% did not sort their wastes. The concentrations of the heavy metals (Co, Zn, Ni, and Mn) in the soil samples were higher in Dolphin and Adeola Odeku village compared to the control soil sample. The bacterial isolates identified from the soil samples are Corynebacterium spp., Enterobacter spp., Flavobacterium spp., Acinebacter spp., Escherichia coli, Proteus spp., Bacillus subtilis and Micricoccus leteus. SWOT analysis revealed the need to improve environmental awareness to minimize the threat of low sorting of wastes. Also, opportunities exist for recycling plastics/pet bottles and nylon while wastes from food materials could benefit agriculture through composing. This study suggests that more environmental awareness, policies, and better administration are needed to improve the status of waste management in urban communities of Lagos Island.

Effects of processing on bacteriological, proximate, hydrocarbon content and organoleptic indices of Scomber scombrus

I.I. James — 2023-02-15

Effects of boiling, smoking and frying on the organoleptic quality, bacteriological count, proximate composition and total hydrocarbon contents of Scomber scombrus fish sold in Ikot Ekpene Metropolis were investigated. Fillets of fresh S. scombrus were made, and processed by smoking, boiling and frying methods. Portions of the fish sample were aliquoted, and used to carry out sensory evaluation, plating aliquots of diluents onto nutrient agar plates (for total viable count (TVC), and on Manitol Salt agar (for total staphylococcal count (TSC). Standard methods were used to determine moisture, ash, total lipids and crude protein contents. Total hydrocarbon content was determined by toluene extraction and measurement of absorbance of filtrate spectrophotometrically. Sensory quality obtained using smoke-drying and frying methods scored significantly higher than that of boiling and the control (p<0.05). TVC of samples were lower than in the control fish sample after processing, increasing over the 4-day period, although negligible when compared to the control. TVC were lowest in samples processed by frying. TSC decreased in all fish samples after processing, except in the control fish sample. Fried Scomber scombrus samples also showed no trace of S. aureus. Moisture, lipid, crude protein and ash contents of control S. scombrus were 68.78±1.02, 2.03±0.11, 20.14±0.06 and 0.09±0.32 respectively. The changes in moisture, lipid, crude protein and ash contents were statistically significant (P<0.05) in processed fish samples. Total hydrocarbon content also increased in processed fish; 2.914±0.005 for smoke-dried, 2.168±0.001 for fried and 1.538±0.009 for boiled, as against 1.412±0.011 in the control sample. Overall bacteriological quality indices, the proximate content and total hydrocarbon contents of samples demonstrated frying and smoking as preferable processing methods for Scomber scombrus.

In vivo assessment of antibacterial and growth promoting effect of soursop (Annona muricata Linn.) leaf extract in broiler chickens

T.T. Kuka — 2023-02-15

Phytochemicals have demonstrated considerable influence against pathogenic microbes in vitro without antimicrobial resistance. A number of studies have also reported an improved growth performance in poultry with their supplementation. In vivo antimicrobial efficacy of soursop leaf extract (SLE) was evaluated in a 49-day study on the growth performance (GP), intestinal microbes and morphology of broiler chickens. Two hundred day-old chicks (Arbor Acres) were randomly distributed to five treatments and four replicates, with ten birds each in a completely randomized design. The treatments included: CTRL (control), 5.0, 7.5, 10.0 and 12.5% SLE per litre of drinking water. Ciprofloxacin 10% was administered to the control group as antibiotics in drinking water at 1ml/2L. Feed intake (FI), weight gain (WG) and feed conversion ratio (FCR) were evaluated. Two birds per replicate were sacrificed on day 49 and eviscerated. Ileum and caeca content were collected and cultured for total coliforms, Lactobacillus, Salmonella and Escherichia coli. Mid-ileum section was cut, rinsed with distilled water and fixed in 10% formalin for evaluation of villus height and crypt depth. Analysis of variance was used for data analysis at p<0.05 confidence. Weight gain increased from 7.5% SLE while FI reduced from 10.0% and above giving the best FCR at 12.5% SLE. SLE improved WG, eliminated salmonella and reduced total coliform (1.30 to 0.00) in the ileum section. Total coliforms were eliminated, Salmonella and Escherichia colli decreased (6.02 to 1.85; 6.91 to 2.24) in the caeca section. It was concluded that SLE reduced pathogenic intestinal microbes, improved intestinal morphology and feed conversion ratio in broiler chickens.

Phytochemical, Nutritional and Trace Element of Some Solanum (Garden Egg)

M.U. Henry — 2023-02-15

Vegetables and fruits form some of the most important components of daily nutrition owing to their high mineral and vitamin contents which are essential for a balanced diet. This research work was carried out on the phytochemicals, proximate and trace element content of three varieties of garden egg which are Solanum melongena (S. melongena), Solanum aethiopicum (S. aethiopicum) and Solanum macrocarpon (S. macrocarpon). The egg plants were extracted and their phytochemical, proximate and trace element content carried out using standard procedures. The result showed that carbohydrates, flavonoids, terpenoids, steroids, anthraquinones, phenols, tannins and proteins were present in the three varieties of the eggplant. Saponin was only observed in S. aethiopicum but not in the other two varieties, while alkaloids were observed to be present in only S. macrocarpon. Cardiac glycosides, anthocyanin and phlobatanins were completely absent in the three varieties. The proximate composition showed that S. melongena contained percentage moisture content (52.23%), ash (23.10%), fibre (3.16%), fat (6.02%), protein (2.38%), carbohydrate (12.05%) while S. aethiopicum contained percentage moisture (59.05%), ash (17.49%), fibre (1.69%), fat (8.05%), protein (2.49%), carbohydrate (11.84%) and S. macrocarpon contained percentage moisture (57.68%), ash (22.71%), fibre (2.05%), fat (5.04%), protein (2.56%) and carbohydrate (10.40%). The trace element content for S. melongena showed magnesium (279.57), calcium (106.80), zinc (4.77), copper (0.88), iron (57.45), manganese (5.53) in parts per million (ppm) while S. aethiopicum contained Mg (258.16), Ca (76.29), Zn (5.55), Cu (1.18), Fe (49.49), Mn (5.43) in (ppm) and S. macrocarpon contained Mg (280.5), Ca (84.95), Zn (3.98), Cu (0.29), Fe (41.49) and Mn (3.44) in (ppm). The findings showed that the three eggplant varieties will serve as a good nutritional diet while S. melongena will supply more trace elements (Fe, Ca, and Mn) and total ash, fibre and carbohydrates. S. aethiopicum has alkaloids and more terpenoids and steroids and hence, will serve as a good medicinal component.

Tomato plant growth promotion potential of Janibacter sp strain RC18

R.C. Osaro-Matthew — 2023-02-15

Actinomycetes are indispensable in the search for novel, potent and eco friendly fertilizers. The aim of this study was to investigate the ability of Janibacter sp. RC18 to enhance tomato plant growth. Janibacter sp. RC18 isolated from turmeric rhizosphere was screened for in vitro and in vivo plant growth promoting traits. The in vitro plant growth promotion traits exhibited by the strain were phosphate solubilization and ammonia production. The strain RC18 inoculated tomato plant recorded significant (P< 0.05) increase in plant height (45.67cm ± 1.5), number of leaves (69.67 ± 3.5), weight (19.40 g ± 0.53), and high soil phosphate solubilizing bacterial count (7.2x10⁵ CFU/g) compared to the uninoculated control. High endogenous plant nutrient content N, P, K, (4.4%, 0.8 % and 1.1%) was also obtained with inoculation of Janibacter. Significant (p< 0.01) positive correlation was recorded with endogenous plant nutrient content and all the plant growth parameters except with the number of flowers. Findings from this study indicate that Janibacter sp RC18 is a good candidate for bio-inoculant formulation .

Isolation and Characterization of Biosurfactant Producing Pseudomonas aeruginosa YLA03 and its Diesel Degradation Potentials

A.A. Arabo — 2023-02-15

This work was aimed at isolating and characterising biosurfactant producing bacteria strain from diesel oil contamination sites. The potential of the strain to degrade diesel oil n-alkanes was further studied. Soil samples were collected from diesel rich areas, and identified strains were grown on minimal media that contained diesel oil as only carbon source. Enrichment culture technique was used to identify bacteria. Seventeen bacteria strains were identified based on their capacity to use diesel oil as carbon source. Other qualitative screening methods were employed to determine the potential to produce biosurfactants. Isolate A03 was the only candidate that shows positive signs for drop collapse, foaming, haemolytic, oil displacement and emulsification tests. The effect of various culture parameters (incubation time, concentration of diesel, nitrogen source, pH and temperature) on biodegradation of diesel was evaluated. Optimum pH was 8.0 at 35° C, while the incubation time at maximum bacteria growth was five (5) days. The favourable diesel oil concentration was 7.5% for the isolate. The isolate has shown degradative ability towards dodecane, Tridecane, tetradecane but was unable to degrade 2, 6, 10-trimethyl- dodecane. It degraded between 10.09% - 45.39% of individual diesel alkanes. The strain has exhibited potential for degrading diesel alkanes and was identified as pseudomonas aeruginosa strain A3 (Accession Number: MZ027605) using the 16S rRNA. Sequencing.

Anacardium occidentale (LINN) Stem Bark Extracts: Effects on Poultry Colibacillosis Disease

A.O. Oko — 2023-02-15

The challenges posed by microbes in poultry industries and the continued search for natural means of combating them inspired this study. The effect of the stem bark extracts of Anacardium occidentale on avian colibacillosis was investigated. Ethanol and aqueous extracts of the stem bark of A. occidentale were prepared using standard methods. In vitro antimicrobial activities of the extracts were evaluated against E. coli. Nine groups of 10 broilers (day old chicks; 48 g – 50 g) each were created and bred for a period of eight weeks. Groups 1 to 3 served as the control, while group 4 to 9 served as the test groups. Meat quality, biochemical and haematological assessments were done using standard methods. The maximum zone of inhibition observed was 13.0±0.4 mm at 100 % concentration of the ethanol extract. Both extracts were observed to have a bactericidal / bacteriostatic ratio of 2. The extracts improved the meat quality, blood protein, liver enzymes and renal functions of the broilers compared to the negative control. Again, packed cell volume, haemoglobin and red blood cell counts were increased by the extracts compared to the negative control. On the whole, the results obtained for the extracts were not significantly different (p > 0.05) from that of the commercial antibiotics (positive control) results. Therefore, we can infer that crude extracts of A. occidentale could be used against Colibacillosis disease in place of the conventional commercial antibiotics.

Effect of Pawpaw Seeds on Management of Alloxan-Induced-Diabetes in Rats

A.O. Oko — 2023-02-15

Ethanol extract of pawpaw seed was evaluated for a possible application in the management of diabetes. Alloxan was used to induce diabetes in rats, which were subsequently used to study the antihyperglycaemic effect of the extract. Four (4) treatment groups and two (2) control groups of 8 rats each were created using complete randomized design. Triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL), low-density lipoprotein (LDL), total protein (TP), glutamic oxaloacetic transaminase (SGOT/AST), glutamic pyruvic transaminase (SGPT/ALT), alkaline phosphatase (ALP), urea and creatinine were studied using standard methods. A single dose of alloxan resulted in a significant increase (p < 0.05) in the serum TG, TC, LDL, AST, ALT, ALP, with a corresponding decrease in serum HDL, urea and creatinine. Following treatment with varying doses of the extract, there was a decrease in serum TG, TC, LDL, AST, ALT, ALP, and an increase in serum HDL, urea and creatinine. It could be inferred from the research outcome that crude extract of pawpaw seed (200 mg/kg extract) could be effective in the management of diabetes.

Characterization of Carabapenem-resistant Enterobacteriaceae in Fresh vegetables

A.E. Ojo — 2023-02-15

Carbapenem-resistant Enterobacteriacea (CRE) has become a growing food safety issue and an ongoing public-health problem of global dimensions. This research study determined the presence of CRE in fresh vegetables. Vegetables were purchased from the retailers and analyzed for Enterobacteriaceae in line with Standard guidelines. The antibiotic profile of the isolated Enterobacteriaceae was determined using Antibiotic Susceptibility Test (AST). The Modified Hodges test (MHT), Carbapenem inactivation method (CIM), Modified carbapenem inactivation (mCIM), and Ethylenediamine tetraacetic acid (EDTA) carbapenem inactivation (eCIM) were used screening for carbapenem resistance among Multidrug-resistant (MDR) Enterobacteriaceae. Forty-six Enterobacteriaceae were isolated in all. Among organisms isolated were Citrobacter freundi, Enterobacter cloacae, Salmonella typhi, Klebsiella sp, and Escherichia coli. AST of the isolates showed that two out of three third-generation antibiotics used had the highest resistance of 100%. Thirty-six (78.26%) were multidrug-resistant, eighteen were CRE using MHT but using CIM, and sixteen were CRE. Eighteen were CRE using the mCIM method, while 17 were using eCIM.

Conclusion: This study shows that vegetables can be a source of carbapenem-resistant Enterobacteriaceae, and mCIM combined with eCIM is more sensitive in detecting CRE.

Significance and Impact of Study: Ready-to-eat fresh Vegetables contain CRE.

Genetic Characterization of Drought-Tolerant Maize Genotypes Based on SSR Markers

O.I. Abegunde — 2023-02-15

Using 20 pairs of SSR primers situated on each chromosome of the maize genetic makeup, 27 drought-tolerant maize genotypes obtained from the Germplasm Unit of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, were examined for diversity. The samples' genomic DNA (gDNA) was extracted using the CTAB procedure specified by CIMMYT (2005). All 20 pairs of SSR markers used in this investigation were extremely polymorphic, resulting in 122 repeatable and polymorphic bands that were scored with an average of 12.20 alleles. Each primer yielded a main allele frequency of no more than 0.5. The average major allele frequency for the 10 primers was 0.3036. With an average of 0.8334, all markers had gene diversity values greater than 0.6. Similar to this, the Polymorphic Information Content (PIC) values had an average of 0.8164 and varied from 0.9051 (primer umc1042) to 0.6639 (Umc1669). Since primer umc1042 best identified this variability, the frequency of the main alleles generated by each primer points to the presence of significant molecular genetic variation across the samples under study. This occurrence is further supported by the gene diversity (GD) and polymorphism information content (PIC) values of the primers. Therefore, it can be inferred that the primers are all appropriate for genotyping genetic diversity. Due to their different genetic relationships, varieties IWD C2 SYN F2 and SAMMAZ 52 have the most diversified genotypes and can be utilised as parent materials in a maize breeding programme.