Growth of Interconnected ZnO Nanostructures-Its Photocatalytic and Electrochemical Properties

We report the synthesis of interconnected ZnO nano structures through the addition of polyvinyl pyrrolidone (PVP) in a growth medium consisting of ZnCl2 and NaOH at a temperature of 70 0C with a reaction time of 24 hrs. The formation of interconnected ZnO is evaluated in accordance with the reaction time and reaction temperature used for the synthesis, and samples were characterized by powder X-ray diffraction, Fourier transform infra- red (FTIR) spectroscopy, Brunauer-Emmett-Teller(BET) analysis, Field emission scanning electron microscopy (FESEM), Photoluminescence (PL) and Electrochemical methods. BET studies show the mesoporous nature of ZnO grown with the addition of PVP in the growth medium. Interconnected ZnO nanostructures exhibit efficient visible light driven photo catalytic degradation of methylene blue (MB) attributed to interconnected morphology of ZnO. Electro chemical studies have shown that the interconnected ZnO nanostructures give higher order specific capacitance.

Effect of Glucose on Endo-xylanase and β-xylosidase Production by Fungi Isolated in Indonesia

Xylanases are widely produced by fungi, and the production of polysaccharide-degrading enzymes, in general, are usually subjected to carbon catabolite repression. In this work, the ability of several Indonesian indigenous fungi to produce endo-xylanase and β-xylosidase and their responses to glucose as a repressor were determined. Ten fungi were grown in a liquid medium supplemented with glucose as the repressor (0, 1%, 3%, and 5%), and the endo-xylanase and β-xylosidase productions were assayed. Aspergillus aculeatus FIG1 and A. oryzae KKB4 produced 3.85 and 0.70 U/mL of endo-xylanase, respectively, compared with other strains (0.22 U/mL or less). Trichoderma asperellum PK1J2, T. virens MLT2J2, A. aculeatus FIG1, T. asperellum MLT5J1, A. oryzae KKB4, and T. asperellum MLT3J2 produced 0.021–0.065 U/mL of β-xylosidase, whereas the other strains produced 0.013 U/mL or less of β-xylosidase. Adding 1% glucose to the growth medium can partially repress endo-xylanase production in A. aculeatus FIG1, T. asperellum PK1J2, and T. virens MLT4J1 and completely repress other strains. By adding 1% glucose, strains FIG1, PK1J2, and MLT4J1 suffered almost complete repression of β-xylosidase production, although such strains exhibited partial repression of endo-xylanase production. β-Xylosidase produced by the other strains showed complete repression by adding 1% glucose, except for A. aculeatus FIG1, A. tamarii FNCC 6151, and T. asperellum MLT1J1, which showed partial repression. Therefore, adding 3% glucose to the growth medium can result in complete repression of endo-xylanase and β-xylosidase productions in all strains examined.

Production of poultry feather hydrolysate using HCl and NaOH as a growth medium substrate for indigenous strains

The poultry feathers have a very high protein content due to it consists of 90% of crude protein, and it is an ideal material to obtain keratin protein. Due to Keratin’s difficulties and time-consuming decomposition, further processing is needed to degrade Keratin into simpler proteins that can be used as an alternative N-source. This study was aimed to evaluate the keratin hydrolysate from poultry feathers prepared by acidic (HCl) and alkaline (NaOH) compound utilization and its potency as the substrate medium for growth keratinolytic bacteria at a laboratory scale. Poultry feathers, including kampung (local breed) chicken feathers, layer chicken feathers, and local goose treat with HCL 12% and NaOH 20%. The results of the hydrolysate of poultry feathers using 12% HCl showed no significant changes. Visually, the feathers of birds that have been treated with 12% HCl show a colour change to brownish-yellow. The results of hydrolysis using NaOH showed better results than HCl for producing feather meals. The highest yield has occurred at local goose feathers at 95.7%, followed by Kampung and Layer chicken feathers at 93.17% and 78,75%. Based on the viability test, three indigenous strains (Bacillus cereus TD5B, B. cereus LS2B and Pseudomonas sp. PK4) grew in a medium with a substrate of kampung chicken feathers, layer chickens, and local goose feathers. It can be concluded that the hydrolysed poultry feathers made by NaOH 20% preparation had a potency as N-source in the bacterial growth medium.

Industrial Hemp (Cannabis sativa L.) Varieties and Seed Pre-Treatments Affect Seed Germination and Early Growth of Seedlings

Seed germination and seedling growth are two essential early determinants of subsequent crop yield and quality. A high germination percentage of industrial hemp (Cannabis sativa L.) seed is required to import into Australia. The viability of hemp seed can decline rapidly depending on storage and other factors; hence, the quality of imported seed is not always reliable. Here, we aimed to investigate germination and early seedling growth responses of 14 industrial hemp varieties after being imported from various countries. Germination trials were conducted with 100 seeds of 14 varieties using a soil-less Petri dish assay and a compost growth medium under glasshouse conditions. We also assessed the effect of seed pre-treatments such as gibberellic acid (500 and 1000 mg·L−1), chlorine dioxide (500 and 1000 mg·L−1) and cold temperature (4 °C for 72 h) using 300 seeds of each of the three selected varieties in compost growth medium. Hemp varieties imported from China had higher germination and better seedling growth indices than those imported from Europe. All seed pre-treatments were associated with a decreasing trend in germination, but a positive effect on early growth responses was observed. Our findings indicate that the hemp variety Han FNQ performed better than many other varieties did regarding seed germination and seedling growth. Hemp seeds sanitising with 500 mg·L−1 of chlorine dioxide might improve the germination and early growth of seedlings.

Biochemical Profile by GC–MS of Fungal Biomass Produced from the Ascospores of Tirmania nivea as a Natural Renewable Resource

The edible fruiting bodies of desert truffles are seasonally collected and consumed in many regions of the world. Although they are very expensive, they are bought and sold as a result of considerable scientific reports confirming their health and nutritional benefits. This study aimed to conduct laboratory production of the fungal biomass of Tirmania nivea as a natural renewable resource of many active biological compounds using an artificial growth medium. The T. nivea collected from Hafar Al-Batin, which is north of Saudi Arabia, and their ascospores were harvested and used to produce fungal biomass in potato dextrose broth. The cultivation was conducted using a shaking incubator at 25 °C for two weeks at 200 rpm. The crud extracts of the fungal biomass and mycelium-free broth were prepared using ethyl acetate, methanol and hexane. Preliminary gas chromatography–mass spectrometry (GC–MS) analysis and their biological activity as antimicrobial agents were investigated. The results showed that the crude extracts have biological activity against mold, yeast and bacteria. The preliminary GC–MS analysis reported that the fungal biomass and extracellular metabolites in the growth medium are industrial renewable resources of several biological compounds that could be used as antifungal, antibacterial, antiviral, anticancer, antioxidant, anti-trypanosomal and anti-inflammatory agents.

Assessment of Phenol Detoxification by Rhodococcus aetherivorans UСM Ac-602 Using the Phytotesting Method

Monoaromatic compounds are related to widespread pollutants of soil and groundwater. Among them phenol is one of the most toxic and carcinogenic compounds. Therefore biodestruction of phenol is of much importance for environment protection. The use of metabolic potential of microorganisms for depolluting environment is a safe and economical alternative to widely used physicochemical methods. Aim. To assess efficacy of phenol detoxification with strain Rhodococcus aetherivorans UСM Ac-602 using the phytotesting method. Methods. Bacteria were cultivated in liquid mineral medium with initial concentration of phenol 500, 750 and 1000 mg/L as a single source of carbon and energy. Cultivation time was 24 h, 48 h and 72 h respectively. Phytotoxicity was determined in express-test with use of seeds of spring wheat variety “Pecheryanka” (Triticum aestivum L.). Plant seeds were incubated by temperature 20±2°C during 7 days in Petri dishes with filter paper treated with respective phenol aqueous solutions or post-fermentative cultural fluids (PFCFs). PFCFs were obtained after cultivation of strain in growth medium with same concentration of phenol. Morphometric parameters of wheat were assessed against control plants cultivated on distilled water. Comparative analysis of samples toxicity and toxicity class determination was performed according to Kabirov method by calculation of index of test factor toxicity (ITF). Results. Phenol aqueous solutions and PFCFs were much different in effect on wheat. Phenol solutions 500 and 700 mg/L have shown significant inhibitory effect on all initial growth parameters of test plants. The weakest growth inhibition was induced by phenol concentration of 500 mg/L which caused decrease in number of germinated seeds by 59.6%, shoot length – by 59.7%, root length – by 84.5%, sprout dry weight – by 35.0%. In the presence of phenol concentration of 750 mg/L these indicators increased by 7−30%; roots of test plants were the most sensitive to effect of phenol. Phenol concentration of 1000 mg/L caused total seed mortality. Unlike phenol aqueous solutions PFCFs have shown insignificant effect on all morphometric indicators of plants compared to control. Similar effects on plants were observed in the presence of PFCFs obtained from cultivation of strain R. aetherivorans UСM Ac-602 in the growth medium with initial concentrations of phenol of 500 and 750 mg/L. Under the influence of these PFCFs, the number of germinated seeds decreased on average by 15.8%, root length decreased by 19.8%, at the same time shoot length and their dry weight increased by 17.8% and 7.2% respectively. More negative effect on wheat was shown by PFCF obtained after strain cultivation on medium with phenol concentration 1000 mg/L. It caused reduction in number of germinated seeds by 18.0 %, shoot length – by 25.3%, root length – by 29.0%, sprout dry weight – by 7.2%. For phenol aqueous solutions ITFs had much lower values 0–0.40 than for PFCFs (0.71–1.0). Conclusions. Based on data obtained in this research it was concluded that strain R. aetherivorans UCM Ac-602 performs active detoxification of high-concentrated phenol-containing media. Analysis of calculation results for ITF medium values (ITFm) had shown that under the influence of studied strain there was a decrease in toxicity of phenol solutions (500, 750 and 1000 mg/L). According to Kabirov toxicity scale it was assessed that toxicity of phenol solutions with initial values of classes II (high) and I (very high) was decreased to IV (low) and V (normal level). Our results demonstrate ecological safety of the end products of phenol destruction with strain R. aetherivorans UCM AC-602 and prospects of its use in biotechnologies for environment detoxification from phenol pollutions.

Production of galactosylated complex-type N-glycans in glycoengineered Saccharomyces cerevisiae

N-glycosylation is an important posttranslational modification affecting the properties and quality of therapeutic proteins. Glycoengineering in yeast aims to produce proteins carrying human-compatible glycosylation, enabling the production of therapeutic proteins in yeasts. In this work, we demonstrate further development and characterization of a glycoengineering strategy in a Saccharomyces cerevisiae Δalg3 Δalg11 strain where a truncated Man3GlcNAc2 glycan precursor is formed due to a disrupted lipid-linked oligosaccharide synthesis pathway. We produced galactosylated complex-type and hybrid-like N-glycans by expressing a human galactosyltransferase fusion protein both with and without a UDP-glucose 4-epimerase domain from Schizosaccharomyces pombe. Our results showed that the presence of the UDP-glucose 4-epimerase domain was beneficial for the production of digalactosylated complex-type glycans also when extracellular galactose was supplied, suggesting that the positive impact of the UDP-glucose 4-epimerase domain on the galactosylation process can be linked to other processes than its catalytic activity. Moreover, optimization of the expression of human GlcNAc transferases I and II and supplementation of glucosamine in the growth medium increased the formation of galactosylated complex-type glycans. Additionally, we provide further characterization of the interfering mannosylation taking place in the glycoengineered yeast strain. Key points • Glycoengineered Saccharomyces cerevisiae can form galactosylated N-glycans. • Genetic constructs impact the activities of the expressed glycosyltransferases. • Growth medium supplementation increases formation of target N-glycan structure.

The selection of laccase producing polypores fungi and inducer addition on the degradation of batik waste

Research on the selection of laccase producing polypores fungi and inducer addition on the degradation of batik waste has been carried out. The objectives of this study were to obtain isolates of polypores fungi with high laccase activity and data on the inducer effect in the batik waste degradation by selected isolate. Batik waste is potential pollution to the environment. It has been found that the Polyporaceae fungus reduce water pollution caused by batik waste. Fungal fruiting bodies were collected at the Cibinong Science Center and forest park IPB Campus Darmaga, Bogor. The inducers used included 15 g/L sucrose, 200 μM CuSO4, and 1.5% sorghum waste. Seven isolates of polypores fungi were obtained. Isolate J6 with high laccase activity was obtained and identified as Coriolopsis sp. The addition of sorghum waste to the growth medium increased the laccase activity of Coriolopsis sp. J6 by 1428 U/mL. Coriolopsis sp. J6 was able to reduce the color of Poly R-478 by 83.73% after the addition of sucrose and incubation for 10 days. This fungus was able to reduce the color of batik waste by 37.17% after the addition of 1.5% sorghum waste and incubation for 10 days.

A novel growth and isolation medium for exoelectrogenic bacteria

A microbiological isolation and growth medium that can effectively discriminate electrochemically active exoelectrogenic bacteria from other non-exoelectrogenic bacteria, is currently unavailable. In this study, we developed a novel chromogenic growth and isolation solid medium based on MnO2 that can selectively allow the growth of exoelectrogenic bacteria and change the medium colour in the process. Known exoelectrogenic bacteria such as Shewanella oneidensis MR1 and other such bacteria from functional microbial fuel cell (MFC) anodes were capable of growing and changing colour in the novel growth medium. On the contrary, non-exoelectrogenic bacteria such as Escherichia coli ATCC 25922 were incapable of growing and inducing a colour changes in the novel medium. Further biochemical characterisation of these isolated exoelectrogenic bacteria by Raman micro-spectroscopy demonstrated that these bacteria over express cytochrome proteins that are vital in extracellular electron transfer events. This medium is a convenient method to isolate exoelectrogenic bacteria from complex environmental samples.