Chelativorans petroleitrophicus sp. nov., a paraffin oil-degrading bacterium isolated from a mixture of oil-based drill cuttings and paddy soil.

We isolated a paraffin oil-degrading bacterial strain from a mixture of oil-based drill cutting and paddy soil, and characterized the strain using a polyphasic approach. The Gram-positive, aerobic, rod-shaped and non-spore-forming strain (SCAU 2101T) grew optimally at 50 °C, pH 7.0 and 0.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence indicated that the strain represented a distinct clade in the genus Chelativorans, neighbouring Chelativorans intermedius LMG 28482T (97.1 %). The genome size and DNA G+C content of the strain were 3 969 430 bp and 63.1 mol%, respectively. Whole genome based phylogenomic analyses showed that the average nucleotide identity and digital DNA-DNA hybridization values between strain SCAU 2101T and C. intermedius LMG 28482T were 77.5 and 21.2 %, respectively. The major respiratory quinone was Q-10. The dominant fatty acids were C19 : 0 cyclo ω8c (50.6 %), summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c; 22.5 %) and C18 : 0 (13.8 %). The polar lipids of the strain included phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, phosphatidylcholine and diphosphatidylglycerol. Based on the results, strain SCAU 2101T was considered to represent a novel species in the genus Chelativorans, for which the name Chelativorans petroleitrophicus sp. nov. is proposed. The type strain is SCAU 2101T (= CCTCC AB 2021125T=KCTC 92067T).

The Cropping Obstacle of Garlic Was Associated With Changes in Soil Physicochemical Properties, Enzymatic Activities and Bacterial and Fungal Communities.

Aims: In garlic cultivation, long-time monoculture has resulted in continuous-cropping obstacles. However, the cause has not been studied to date. Methods: We analyzed soils from garlic fields in Pengzhou, China, to determine continuous-cropping obstacle related changes in soil physicochemical properties and enzyme activities, and in the diversity and composition of bacterial and fungal communities. Furthermore, we examined the relationships between soil properties and the bacterial and fungal communities. Results: The soil pH and the soil catalase, urease, invertase, and polyphenol oxidase activities were lower in the cropping obstacle soil than in the healthy control soil. The richness and diversity of the bacteria were lower in the cropping obstacle soil than in the control. The bacterial and fungal communities in the cropping obstacle soil were clearly different from those in the control soil. The differences in bacterial communities between the cropping obstacle soil and the control soil were associated with differences in pH and available potassium content. The taxa with higher relative abundances in the cropping obstacle soils included potential plant pathogens and the taxa with lower relative abundances included potential plant growth promoters. Conclusion: The enrichment of plant pathogens and the depletion of plant growth promoting fungi may have contributed to the poor growth of garlic in the cropping obstacle soil. The enzyme activity and microbial community differences were associated with acidification that was likely an important factor in the deterioration of the soil ecological environment and the garlic cropping obstacle. The results provide information to guide agricultural practices in cultivating garlic.

Bio-Matrix Pot Addition Enhanced the Vegetation Process of Iron Tailings by Pennisetum giganteum.

The barrenness of large mine tailing sand reservoirs increases the risks for landslides and erosion that may be accompanied with transfer of contaminants into the surrounding environment. The tailing sand is poor in nutrients, which effectively complicates the vegetation process. We investigated direct planting of Pennisetum giganteum into tailing sand using two pit planting methods: the plants were transplanted either directly into pits filled with soil or into soil-filled bio-matrix pots made of organic material. After growing P. giganteum in iron tailing sand for 360 days, the dry weight of the plants grown in the bio-matrix pot (T2) was approximately twofold higher than that of the plants grown in soil placed directly into the sand (T1). At 360 days, the organic matter (OM) content in the soil below the pit was the lowest in the not-planted treatment (T0) and the highest in T2, the available N (AN) contents were higher in T1 and T2 than in T0, and the available P and K contents were the highest in T2. At 360 days, the Shannon diversity of the soil microbial communities was higher in T1 and T2 than in T0, and the community compositions were clearly separated from each other. The profiles of predicted C cycle catabolism functions and N fixation-related functions in T1 and T2 at 360 days were different from those in the other communities. The results showed that P. giganteum grew well in the iron tailing sand, especially in the bio-matrix pot treatment, and the increased nutrient contents and changes in microbial communities indicated that using the bio-matrix pot in planting had potential to improve the vegetation process in iron tailing sands effectively.

Demulsification of oily wastewater using a nano carbon black modified with polyethyleneimine.

In this work, nano carbon black was modified with polyethyleneimine (CB-PEI) under an ultrasonic field. The obtained product was used as a demulsifier to break oily wastewater. Morphology, structure, and chemical composition of CB-PEI were systematically analyzed. Bottle test was carried out to evaluate the influence of dosage, pH value and salinity on the demulsification efficiency of the emulsion. The results showed that the light transmittance of water phase (TSW) after the demulsification was 79.1% and corresponding oil removal rate (ORR) could reach up to 99.4% with 60 mg/L of CB-PEI at ambient temperature for 30 min. In addition, the possible demulsification mechanism was explored by dynamic interface tension (IFT), elasticity modulus, wettability, self-assemble of interfacial membrane, zeta potential and micrograph analysis. It indicated that CB-PEI had an appropriate amphiphilicity and good interfacial activity, which could improve it quickly transfer to the oil-water interface and result in the oil-water separation. The current work provides a simple method to prepare a demulsifier with excellent performance, so it has a good application prospect for the treatment of oil-water emulsions.

Electrolarynx in voice rehabilitation.

OBJECTIVE: Patients of laryngeal cancer who have undergone the surgical removal of the entire larynx suffer the loss of phonation. Electrolarynx (EL) speech is the most commonly adopted alaryngeal phonation. However, EL speech is notorious of the sound quality being monotonic and robotic with the lack of pitch control and the presence of the radiated noise. This paper provides a review of modalities in EL speech as well as introducing the technologies to control the pitch and reduce the noise of the device. METHODS: Improvements of EL speech quality have been divided into two parts: improving the sound quality of EL device by applying different enhancement algorithms to reduce the radiated and the additive noise, and implementing pitch-control function to the EL with advanced technology. RESULTS: Adaptive filtering and the subtractive-type algorithms have shown to be able to reduce the noise level associated with EL speech. And more mature technologies are showing promise to the making of a hand-free EL system producing more accurate and synchronized pitch and voice onset control. CONCLUSION: The advent of micro-technology and human-machine integration promisingly improves EL speech quality and more efficient algorithms enhance EL sound quality. Such improvements apparently improve the intelligibility of EL speech, and thus better quality of life of the EL speakers.