Hydrolysis of newspaper polysaccharides under sulfate reducing and methane producing conditions

Assessment of Temporal Effects of a Mud Volcanic Eruption on the Bacterial Community and Their Predicted Metabolic Functions in the Mud Volcanic Sites of Niaosong, Southern Taiwan

The microbial communities inhabiting mud volcanoes have received more attention due to their noteworthy impact on the global methane cycle. However, the impact of temporal effects of volcanic eruptions on the microbial community’s diversity and functions remain poorly characterized. This study aimed to underpin the temporal variations in the bacterial community’s diversity and PICRUSt-predicted functional profile changes of mud volcanic sites located in southern Taiwan using 16S rRNA gene sequencing. The physicochemical analysis showed that the samples were slightly alkaline and had elevated levels of Na⁺, Cl⁻, and SO₄²⁻. Comparatively, the major and trace element contents were distinctly higher, and tended to be increased in the long-period samples. Alpha diversity metrics revealed that the bacterial diversity and abundance were lesser in the initial period, but increased over time. Instead, day 96 and 418 samples showed reduced bacterial abundance, which may have been due to the dry spell that occurred before each sampling. The initial-period samples were significantly abundant in haloalkaliphilic marine-inhabiting, hydrocarbon-degrading bacterial genera such as Marinobacter, Halomonas, Marinobacterium, and Oceanimonas. Sulfur-reducing bacteria such as Desulfurispirillum and Desulfofarcimen were found dominant in the mid-period samples, whereas the methanogenic archaeon Methanosarcina was abundant in the long-period samples. Unfortunately, heavy precipitation encountered during the mid and long periods may have polluted the volcanic site with animal pathogens such as Desulfofarcimen and Erysipelothrix. The functional prediction results showed that lipid biosynthesis and ubiquinol pathways were significantly abundant in the initial days, and the super pathway of glucose and xylose degradation was rich in the long-period samples. The findings of this study highlighted that the temporal effects of a mud volcanic eruption highly influenced the bacterial diversity, abundance, and functional profiles in our study site.

Impact of changes in fermentation time, volume of yeast, and mass of plantain pseudo-stem substrate on the simultaneous saccharification and fermentation potentials of African land snail digestive juice and yeast

This study was carried out to investigate the effect of variations in mass of plantain pseudo-stem waste, volume of yeast used, and fermentation time on the product yield resulting from simultaneous saccharification and fermentation using digestive juice of African land snail and yeast. The experiment was divided into three stages which included a total of fifty seven (57) experimental setups containing sixteen (19) different combinations of the varied substrates. The results show that by varying the mass of plantain pseudo-stem waste, the production of ethanol was optimized at a mass of 250 g, which yielded 125.6 ml ± 3.5 of distillate and a percentage ethanol composition of 25.0 ± 3.6. While varying the volume of yeast used between 50 and 250 ml, with 250 g of plantain pseudo-stem waste, 250 ml of snail digestive juice and 4 g garlic for 24 h, acetic acid was detected in the setup containing 200 ml of yeast, but was not detected in similar experimental setups containing 6 g garlic. The optimum ethanol production while varying the volume of yeast slurry was recorded to be 182.3 ml ± 4.9 of distillate with 28.0% ± 1.0 ethanol composition. Variations in fermentation periods had the greatest impact on the percentage composition of ethanol and the volume of ethanol produced showing the best fermentation period for obtaining optimal ethanol production to be at 96 h. These findings show that the best specifications for the optimum production of ethanol from a 250 g of plantain pseudo-stem waste using 250 ml snail digestive, are 200 ml of yeast slurry, 6 g of garlic to ferment for a period of 96 h.

Anaerobic biodegradation of soybean biodiesel and diesel blends under sulfate-reducing conditions

Biotransformation of soybean biodiesel and its biodiesel/petrodiesel blends were investigated under sulfate-reducing conditions. Three blends of biodiesel, B100, B50, and B0, were treated using microbial cultures pre-acclimated to B100 (biodiesel only) and B80 (80% biodiesel and 20% petrodiesel). Results indicate that the biodiesel could be effectively biodegraded in the presence or absence of petrodiesel, whereas petrodiesel could not be biodegraded at all under sulfate-reducing conditions. The kinetics of biodegradation of individual Fatty Acid Methyl Ester (FAME) compounds and their accompanying sulfate-reduction rates were studied using a serum bottle test. As for the biodegradation of individual FAME compounds, the biodegradation rates for the saturated FAMEs decreased with increasing carbon chain length. For unsaturated FAMEs, biodegradation rates increased with increasing number of double bonds. The presence of petrodiesel had a greater effect on the rate of biodegradation of biodiesel than on the extent of removal.

Microbial community compositional analysis for series reactors treating high level antibiotic wastewater

A full-scale biosystem consisting of two anaerobic reactors (HA and BF1) and four aerobic ones (BF2-BF4 and OD) in succession and receiving antibiotic-bearing (mainly streptomycin) wastewater was used for studying the impacts of antibiotics on microbial community structures. Significant decreases of streptomycin (from 3955 ± 1910 to 23.1 ± 4.7 μg L(-1)) and COD(Cr) were observed along the treatment process. Cloning results show that the anaerobic reactors (HA and BF1) were dominated with Deltaproteobacteria (51%) mainly affiliated with sulfate-reducing bacteria (SRB), while the aerobic BF2 receiving streptomycin of 408.6 ± 59.7 μg L(-1) was dominated with Betaproteobacteria (34%), Deltaproteobacteria (31%) and Bacteroidetes (14%). Gammaproteobacteria (15.9-22.4%), Betaproteobacteria (10.0-20.3%), and Bacteroidetes (4.5-29.7%) became the major bacterial groups in aerobic BF3-OD receiving streptomycin of ≤83 ± 13 μg L(-1). Archaea affiliated with Methanomethylovorans hollandica-like methylotroph was abundant in HA and BF1 (archaea/bacteria, 0.54-0.40; based on specific gene copy number), suggesting the coexistence of SRB and methanogens in degrading pollutants. Fungi were abundant (fungi/bacteria, 0.15; based on specific gene copy number) with the dominance of Ascomycota (clone ratio of Ascomycota/eukarya, 25.5%) in BF2, suggesting that fungi could be an important player in pollutant removal under high levels of antibiotics. This study demonstrates that under high antibiotic levels, wastewater treatment communities may maintain system stability through adjusting bacterial, archaeal, and eukaryal compositions.

Sugarcane bagasse oxidation using a combination of hypochlorite and peroxide

Reactive oxygen species (ROS) such as singlet oxygen ((1)O(2)), superoxide (O(2)(-)), hydroxyl radicals (OH(*)), or hypochlorite ion (OCl(-)), can remove both hemicellulose and lignin from lignocellulose. Ox-B (US Patent 6,866,870), an ROS producing solution containing sodium hypochlorite and hydrogen peroxide, was investigated for its ability to oxidize sugarcane bagasse. Treatment with equivalent amounts of hypochlorite produced similar results. Ox-B differentiated from hypochlorite when low concentration treatments were used and they were followed by a caustic wash. Cellulases hydrolyzed 80-100% of the cellulose present after Ox-B/caustic treatment compared to 40% or less for NaOCl/caustic treatment. Ox-B treatment was temperature independent and complete within 3h. It was pH dependent, with best results obtained when the pH was controlled at 8. Although highly effective, in order for Ox-B to be industrially feasible for alcohol production, the chemical cost must decrease to justify its use.