Biotechnology Journal International

Aims: The research was aimed to study the effects of antistaling agent on the fresh-keeping of cutting branches in order to provide the foundation on sticks-cutting preservation in production.

Study Design: In order to analyze the function and action mechanism of antistaling agent A(3% sucrose +50mg·L^-1 aluminium sulfate + 200mg·L^-1 citric acid + 100mg·L^-1 GA) and B (3% sucrose + 0.5% benzene propionic acid sodium), we used the Cornus alba L., as materials, observed fresh-keeping life and morphological changes, measured the fresh weight, the contents of chlorophyll, soluble sugar, red pigment and anthocyanin in cutting branchs of Cornus alba L.

Place and Duration of Study: College of Biological Science and Technology, Shenyang Agricultural University, between February 2017 and March 2018.

Methodology: The contents of soluble sugar, chlorophyll, anthocyanin and red pigment in stem bark were determined at 3d, 6d, 9d, 12d and 15d after treatment, respectively. The contents of chlorophyll, red pigment and anthocyanin in cutting branchs of Cornus alba L. were measured by method of spectrophotometer. The content of soluble sugar was determined by anthrone colorimetry.

Results: The effects of antistaling agent A (3% sucrose +50mg·L^-1 aluminium sulfate + 200mg·L^-1 citric acid + 100mg·L^-1 GA) and antistaling agent B (3% sucrose + 0.5% benzene propionic acid sodium) were tested in this paper in order to investigate their effects on contents of chlorophyll, soluble sugar, red pigment and anthocyanin in cutting branchs of Cornus alba L., which provided foundation on sticks-cutting preservation in production. Early spring sticks of Cornus alba L. were used as materials by antistaling agent A and B treatment, respectively, and sterilized water as control. Results showed that contents of chlorophyll and soluable sugar in the antistaling agent A group were higher than those in B group. And the contents of anthocyanin and red pigments in the antistaling agent B group were higher than those in A group. Above all, the antistaling agent B had better preservation effect than the antistaling agent A.

Conclusion: The contents of chlorophyll and soluable sugar in the antistaling agent A group were higher than those in the antistaling agent B group. And the contents of anthocyanin and red pigments in the antistaling agent B group were higher than those in A group. Above all, the antistaling agent B had better preservation effect than the antistaling agent A.

In this study, sweet potato was purchased and processed using different methods to obtain 4 different sweet potato flour samples. Sample A was unfermented sweet potato flour, sample B was fermented spontaneously, while sample C and D were produced by fermentation using indigenous starter cultures of lactic acid bacteria and yeast for 48 h and 72 h respectively. Colour profile, Pasting and Sensory evaluation was conducted. The whiteness (L* value) obtained in this study is within the range of value (87.29-89.52), Also, the redness value (a*) and yellowness value (b*) of the sweet potato flour samples also showed a significant difference (p<0.05). Sample a had a higher value when compared with samples B,C and D. Pasting properties such as peak viscosity, trough viscosity, breakdown viscosity, setback, pasting temperature were determined. It was noticed that fermentation process and increase in fermentation time significantly (p<0.05) decrease the peak viscosity in this research work and all samples had a higher cooled paste viscosity than their corresponding hot paste viscosity. Nevertheless, sensory evaluation was carried out using thet 9-point hedonic scale, samples A,B,C,D are significantly different (P < 0.05).

Runner tips explants of strawberry give rise to multiple shoots when cultured on MS medium supplemented with different concentrations and combinations of BAP with KIN or NAA or GA3.The highest response of shoot multiplication was obtained on MS containing 2.5 mgl-1 BAP + 0.5 mgl-1 Kin + 0.5 mgl-1 GA3. The maximum frequency of rooting (83%) and highest number of roots (3.49) was produced in medium containing 1.0 mgl-1 IBA. The well grown rooted plantlets were acclimatized and successfully established in autoclaved vermiculate soil and as well as natural condition. Using our established protocol, it is also possible to provide large numbers of micropropagated plantlets of this cultivars to produce high quality strawberry fruit for commercial cultivation practices.

Aims: To determine effects of aromatic hydrocarbons and marine sediments from Niger Delta on the growth of microalga Phaeodactylum tricornutum.

Study Design: Fifteen treatments and the control were designed in triplicates in which long cells containing 25 mL of the algae-toxicant dilutions were supplemented with 0.0 mg /L, 1.0 mg /L, 1.8 mg /L, 3.2 mg /L, 5.6 mg /L, and 18.0 mg /L of xylene, anthracene and pyrene each; three sediments and potassium dichromate incubated for 3 days at 20 ± 2°C. The fifteen treatments and control (K₂Cr₂O₇) designated as C0, C1, C2, C3, C4 and C5 were used to determine their median effective concentration (ErC₅₀) on the growth of microalga Phaeodactylum tricornutum.

Place and Duration of Study: Department of Microbiology, Chukwuemeka Odumegwu Ojukwu University, Uli Nigeria between February, 2018 and July, 2018.

Methodology: A laboratory scale study was carried on the sediment samples from the three studied areas using physiochemical analysis and marine microalga toxicity test.

Results: The findings revealed that the three sampling sites contain higher quantities of aromatic hydrocarbons, heavy metals and other physio-chemical parameters in the sediment samples than water samples. The K₂Cr₂O₇had the highest ErC₅₀ value of 08.07 ± 0.03 mg /L with CV and r² values of 68.61% and 0.99 while pyrene in Nembe sediment had the least ErC₅₀ value of 04.63 ± 0.01 mg /L with CV and r² values of 78.27% and 0.98 with very strong significant positive linear relationship between algal number and sample concentrations (P = .05).

Conclusion: Thus, the toxicity results (> 1 mg /L <EC₅₀ ≤ 10 mg /L) in this study are in line with other toxicity values for this type of toxicants, and are therefore considered to be scientifically relevant in ecotoxicological risk assessment of Niger Delta, Nigeria.

The search for efficient and green oxidation technologies has increased interest in utilization of laccases in non conventional methods. Laccases catalyze a wide range of substrates due to low substrate specificity and strong oxidative potentials. Challenges to large-scale enzyme utilization include, low enzyme activity and instability which restrict use in many areas of biotechnology. In the study, 59 fungi comprising Aspergillus niger (40%), Trichoderma harzianum (31%), Aspergillus flavus (9.0%), Trichoderma viride (5.0%), Fusarium oxysporum (5.0%), Rhizopus stolonifer (5.0%), Trametes sp. (3.0%) and Aspergillus nidulans (2.0%) were isolated and screened for laccase production. Plate screening test showed 57.5%, 34.0% and 8.5% of fungi were laccase-positive on ABTS, Guaiacol, and α-naphthol agar respectively. Isolates were further screened in liquid cultures, and the highest laccase producer identified molecularly. Trametes sp isolate B7 was selected for solid state fermentation (SSF). Laccase production in SSF was highest at pH 5.0 (2356 U/mL). The purified laccase showed high activity (pH 3.0 - 6.0) and stability (pH 3.0 - 8.5) using ABTS. It was active (20 - 80°C) and thermostable (30 - 80°C) with optimum stability at 70°C (100% for 1 hour). The percentage decolourization of Phenol red were 28% and 36% using 1000 U/mL and 2000 U/mL crude laccases respectively. Similarly, RBBR (100%), Congo red (75%) and Malachite green (62%), and 77.4%, 64% and 28% were decolourized using 1000 U/mL and 2000 U/mL crude laccases respectively. ABTS agar was very reliable in large-scale screening for laccase which possessed thermostable property and degraded synthetic dyes without use of enzyme mediators. These attribute made the enzyme suitable for application in industry and biotechnology.