Biotechnology Journal International

Aims: Pests are one of the factors that cause problems in plant production. Many methods are used in the fight against economically damaging insects. Mixtures of various substances are used to reduce the negative effects of harmful organisms and to control them. These substances, called pesticides, often have a chemical origin, because they have many direct and indirect damages to human and nature. In the future, thanks to the encapsulation of microbial metabolites into nanoparticles, it is likely that nano-biopesticides based on new nanobiotechnological methods will emerge as alternatives to conventional pesticides.

Opinion: Could the bacterial origin chitinase enzyme (Nano-Bio formulation) immobilize to zinc oxide nanoparticles be used against harmful insects in agricultural production in the future? Can it be used to break down the chitin structure in the intestinal cells of harmful insects, suppress intestinal enzymes that are important to insects (LDH, AT, AP) and cause death by breaking down the throat?

Call to the Future: New pesticide formulations can be created as a renewable natural product against plant pests using various protein structures that humans produce from microorganisms isolated from their gene sources. The stabilization of the product can be maintained by immobilizing the nanoparticles to increase the effectiveness of the pest. Thus, the risk potential of pollution created by traditional pesticides will be reduced. The use of Nano-bio pesticides will bring a different perspective in the field of industry. By establishing various production centres based on bioprocesses of renewable resources, it can lead to an effective struggle in agricultural production and increase global employment on a global scale.

What do we have to do?: As scientists, believing in the power of microorganisms, the investigation of the potential of microbial metabolites to be used as pesticides and their effectiveness and stability with nanoparticles is important for the 10-year process ahead.

Introduction: The biological green synthesis of nanoparticles via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. Annona muricata, a tropical plant belonging to family Annonaceae is one of the most used plants in folk medicine because of its many medicinal uses and therefore presents a strong candidate for use in green synthesis.

Aims: The aim of this study was to optimize a method for the synthesis of Silver Nanoparticles (AgNPs) from ethanolic extracts of leaves of Annona muricata as well as to characterize the green synthesized AgNPs.

Methodology: AgNPs were synthesized from Annona muricata leaves using AgNO₃ solution. The AgNPs were characterized using spectroscopy and microscopy techniques.

Results: The formed AgNPs had an absorption maximum at 429 nm using UV–Visible spectroscopy and were stable under different pH, temperature, and storage conditions. Fourier transform infrared analysis revealed the different functional groups responsible for the synthesis and stabilization of the AgNPs. Scanning electron microscopy analysis revealed a spherical nature of the synthesized AgNPs. Energy dispersive x-ray spectroscopy analysis showed presence of Ag, O, and Cl with Ag having the highest composition at 60%. X-Ray Diffraction and Dynamic Light Scattering revealed a crystalline nature of AgNPs with an average size of 87.36 nm and a polydispersity index of 0.16 respectively. Transmission Electron Microscopy analysis further confirmed the crystalline and spherical nature of the AgNPs.

Conclusion: In this article, an efficient, eco-friendly and low-cost method for the synthesis and recovery of stable AgNPs using Annona muricata leaves ethanolic extracts as both a reducing and capping agent has been reported for the first time. The synthesized AgNPs could be promising candidates for many biomedical, clinical, engineering, and polymer applications.

Aim: Viability of hydrocarbon-degrading bacterial consortium immobilized on different carriers was studied.

Methodology: Hydrocarbon-degrading bacteria were isolated from crude oil contaminated sites in Gio and K-Dera, Rivers State, Nigeria using enrichment method. Proximate analyses were carried out on the best carrier materials. Immobilization was by direct adsorption of the isolates onto the carrier materials and viability was determined by plate count method. The carrier materials tested included soya bran, sugarcane bagasse, corn cob, brown saw dust, white saw dust, cassava peel and red mud (bentonite).

Results: The bacterial isolates demonstrated varied degradation capacity. The best carrier material was saw dust (103.6% survival) and corn cob (103.6% survival) followed by soya bran (94.4% survival rate) and cassava peel (94.4% survival rate). The saw dust had moisture content, 5.92%; ash content, 7.49%; crude protein, 2.2%; volatile matter, 74.28; and fixed carbon, 12.34%; whereas, the percentage chemical composition observed for soya bran were 10.11, 4.08, 5.22, 42.61, 18.37 and 8.89 for moisture content, ash content, crude fibre, crude protein, crude fat and carbohydrate, respectively. There was significant difference (p=0.05) between viability rate observed with the different carrier materials.

Conclusion: This study showed that the agro-wastes used in this study can effectively enhance the viability of hydrocarbon-utilizing bacterial. The result is significant as it shows the possibility of using these carrier materials for bioremediation of hydrocarbon contaminated media.

Wheat is one of the most important staple grains in the world and the leading source of calories, production is limited by biotic stress. There is a number of pathogen attacks on wheat crops, depending on environmental conditions. In some cases, more than one crop pathogen attack leads to higher damage or decrease susceptibility. There are very few studies in the field of multiple pathogen interactions; in this study, we analyzed the co-infectionof wheat with fungal and bacterial pathogens. Field isolated Xanthomonas translucens and Xanthomonas compestris bacteria have been used against GM-322 and PDKV varieties co-infected with Fusarium fungus spp.  In our experiment, we used Fusarium oxysporum, Fusarium graminearum, Fusarium equitus. Compared to the combined effect of the fungus and bacteria, we measured the length and width of the infected leaf part. We have observed that there is more susceptibility to X. compestris and F. graminearium in the GM-322 wheat variety. The second susceptible cvs was PDKV when we co-infected F. oxysporum and then X. translucens fungal and bacterial infected symptom analysis showed yellow stripes on the leaf surface of the wheat crop. We observed head blight in wheat when it was infected with F. graminearum and X. compestris. As a result, we concluded that varietal susceptibility also depends on co-infection pathogen attacks and their synergetic interaction.

Aims: The study aims to assess the ability of Acacia dudgeoni bark to antagonize quorum sensing system, expression of virulence factor and biofilm formation.

Place and Duration of Study: The study was conducted at the Laboratory of Applied Biochemistry and Chemistry (LABIOCA), University Joseph KI-ZERBO between December 2018 to April 2019.

Methodology: Methanol extract from A. dudgeoni stem bark, was used for the investigations. The reporters strain Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1 were used to measure the impact of extract on quorum sensing controlled violacein and pyocyanin production. P. aeruginosa PAO1 was used to measure the impact on biofilm formation.

Results: At different concentrations (50-400 µg/mL) A. dudgeoni methanol extract quenched the quorum sensing mechanism. Significant inhibition of virulence factor, pyocyanin was recorded (66% of inhibition at 400 µg/mL) without affect negatively the growth of P. aeruginosa PAO1. The formation of biofilm was also affected with a reduction up to 59% at the concentration of 400 µg/mL.

Conclusion: The anti-quorum sensing and anti-biofilm properties of this medicinal plant could serve as a source in the developpement of new effective anti- quorum sensing drugs.

Aims: To identify crude oil-degrading bacteria isolated from polluted soils and waters and screen the presence of catechol 2, 3 dioxygenase (C23O) gene encoding oil-degradation in the strains with the highest degradative activity.

Study Design: Laboratory-experimental design was used in this study.

Place and Duration of Study: Crude oil polluted soils and waters were collected from Awoye, Mese and Oluwa villages in Ondo State, Nigeria and three different flow stations (Agbada-Aluu shell, Obite, and Bonny) in Rivers State, Nigeria.

Methodology: The identities of the isolates were confirmed by extracting their total genomic DNA using standard DNA protocols while a portion of 16S bacterial gene of their DNA was amplified by polymerase chain reaction (PCR) using the primers E9F and U1510R and sequenced using Sanger method. Degenerate primers were used to isolate and identify the gene encoding C23O, responsible for the degradation of oil. Molecular cloning of the gene was done by transforming into Escherichia coli DHα. The correct inserts from the selected clones were performed by colony PCR. The isolated gene was sequenced with a Dye terminator sequencing kit and the product was analyzed with Prism DNA sequencer.

Results: The results obtained from the conserved sequence of the 16S rRNA coupled with the nucleotide sequence revealed ten (10) crude oil-degrading bacteria, with CFfab 14 and CFfab 12 having the highest and lowest degrading activity of  78.92 ± 0.9 Unit/mL/h and 43.89 ± 1.3 Unit/mL/h on day 3 respectively.

Conclusion: The gene C23O responsible for the production of catechol 2, 3 dioxygenase was isolated from strains CFfab 5, CFfab 14 and CFfab 15. The nucleotide base sequence of the gene was determined to be 238 bp. It is expected that in bioremediation, indigenous microorganisms from polluted environments should be screened for the possible existence of this unique gene sequence for effectiveness. Further studies could be conducted on the possibility of cloning this C23O gene into other bacteria for more efficiency and effectiveness in the bioremediation process.

In this study, a laccase producing white rot fungus from the wood degrading family of dermatophytic Trichophyton sp. was isolated. The laccase which was produced via solid state fermentation using rice bran as the lignocellulosic support was partially purified before its effectiveness in degrading an azo dye (methyl orange) was examined. Time course study showed that day nine (day 9) gave the maximum enzyme production. The crude laccase was purified by ammonium sulfate precipitation and dialyzed against sodium phosphate buffer pH 7. Optimum pH and temperature of the were 4.5 and 55°C respectively as assayed using ABTS (2,2 azino bis-3-ethyle benzothiozoline-6-sulfonic acid) as substrate. Dye degradation assay was carried out by introducing 0.5 ml of the enzyme into three dye concentrations: 50 mg/L, 100 mg/L and 200 mg/L and monitoring them for up to 48 hours by taking their absorbances at intervals at 5mins, 5hours, 24hours and 48 hours after enzyme introduction. At the end of the experiment, good dye degradation by laccase from Trichophyton sp. was observed to be positive with 50 mg/L being the most effective concentration during the study. The result are positive indicators of the fact that locally isolated white rot fungi has the capacity to be used for many biotechnological dye degradation and removal studies.

With different culture conditions and concentrations of growth regulators and supplements, Anther culture technique can be easily employed for the production of haploids under in vitro conditions.

Aims: The present study was undertaken with the objective to optimize the development of doubled haploids using anthers for in vitro induction of callus on N₆ medium.

Place and Duration of Study: The samples (BC₂F₁ seeds) were raised previously in Skuast-J. From total degree program of 3 years, this work related to tissue culture technique was done in one year from January 2018 to January 2019.

Methodology: The effect of levels of 2, 4-dichlorophenoxy acetic acid (2, 4-D) i.e. 0 to 3 mg/L in basal N₆ media was observed on callus induction frequency (CIF). The effect of duration of cold pre-treatment was observed on callus induction frequency at 2.5 mg/L of 2, 4-D by giving the cold pre-treatment at 4ºC from 8 to 12 days. Also the effect of different amino acids was checked on callus induction frequency.

Results: Highest callus induction frequency of 9.39 per cent was observed in N₆ medium fortified with 2.5 mg/L 2, 4-D and lowest callus induction frequency of 2.52 per cent at the concentration of 1.0 mg/L. The cold pre-treatment for 10 days gave highest callus induction frequency of 1.44 per cent and lowest callus induction frequency of 0.44 per cent was obtained at cold pre treatment for 8 days. The highest callus induction frequency of 12.55 per cent was observed in case of media supplemented with 25 mg/L tryptophan and 40 mg/L cysteine and lowest callus induction frequency of 7.18 per cent was observed when media was supplemented with 560 mg/L proline.

Conclusion: The cold pre-treatment of 10 days at 4ºC on media supplemented with 2.5 mg/L of 2, 4-D and combination of 25 mg/L tryptophan and 40 mg/L cysteine proves to provide best androgenesis conditions for anthers from BC₂F₁ population.

Salinity is one of the most vicious environmental factors controlling the productivity of crop plants as most of the crop plants are sensitive to salinity affected by high concentrations of salts in the soil. The objective of this study was to evaluate the influence of the inoculation with the encapsulated and liquid culture of three halo-tolerant plants growth-promoting rhizobacteria (PGPR) strains of Paenibacillus polymyxa MSRH5, Bacillus nakamurai MSRH1 and Bacillus pacificus MSR H3 on the growth and yield of wheat (Triticum aestivum L.). The three strains MSRH1, MSRH3 and MSR H5 were characterized as salt-tolerant bacteria. P. polymyxa MSRH5 had nitrogen fixation ability while B. nakamurai MSRH1 and B. pacificus MSRH3 were able to solubilize phosphate and K respectively. All strains can produce indole acidic acid (IAA) and exopolysaccharides (EPS) under saline conditions. Encapsulated beads were observed under Scanning Electron Microscope (SEM). Colonization of encapsulated bacteria on the root of the wheat plant was studied by Transmission Electron Microscopy (TEM). Under soil salinity conditions in two consecutive field tries, results cleared that strains in two forms succeed to colonize the plant root, the reduction in shoot proline was 35.8% with capsules inoculation as well as improved relative water content (%) to 60.57% and improved the electrolyte leakage recorded 18.1% respectively compared to control. Generally, halo-tolerant PGPR inoculation increased DHA (?), acidic and alkaline phosphatase activities compared to control, inoculation with capsules exhibited a reduction in catalase enzymes 46.00%, 37.5% in ascorbate peroxidase and 40% in superoxide dismutase respectively in shoots of the wheat plant. There is a significant increase in all yield parameters, the highest plant height 115.8 cm, spike length 21 cm and 1000 grains 71.3 g respectively recorded with capsules inoculation, it had considerable effects on the content of N, P, K and Na in shoots of wheat plants and reduced the value of Na/K ratio in all treatments inoculated compared to un-inoculated wheat plant.