Interspecies microbial interactions in bioelectrochemical system and biodegradation: A state of the art review.

Microbial mutualistic interaction or synthetic microbiology evolves closely from the concept of cell-cell relations in a complex microbial community, which plays a crucial role in waste degradation, bioremediation, and bioenergy generation. Recently, the application of synthetic microbial consortia has renewed attention in the field of bioelectrochemistry. In the past few years, the influence of microbial mutualistic interaction has been extensively studied in bioelectrochemical systems (BES), especially in microbial fuel cells (MFCs). Nevertheless, synthetic microbial consortia were found to exhibit superior bioremediation performance compared to single strains of microbes for polycyclic aromatic hydrocarbons, synthetic dyes, polychlorinated biphenyls, and other organic pollutants compared to the respective single microbial species. However, a comprehensive understanding of intermicrobial interactions, specifically the metabolic pathways in a mixed-cultured microbial community system, is still lacking. In this study, we have comprehensively reviewed the possible pathways for executing intermicrobial communication within a complex microbial community consortium with various underlying pathways. The influence of mutualistic interactions on the power generation of MFCs and wastewater biodegradation has been widely reviewed. We argue that this study would motivate the design and construction of potential synthetic microbial consortia to stimulate the extraction of bioelectricity and the biodegradation of contaminants.

A Flow Injection Chemiluminescence Method for the Determination of Retinol in Pharmaceutical Formulations by Using Luminol-Diperiodatoargentate(III) Reaction.

In this paper, a chemiluminescence (CL) method is proposed for retinol determination by combining flow injection (FI) methodology. The CL reaction is based on the oxidation of luminol by diperiodatoargentate(III) (DPA) in the presence of retinol. Under the optimum conditions, the relative CL intensity was linear to the concentration of retinol over the range 5.0×10-3-14 mg L-1 (y=347.26x+2.5944, R2=0.9999, n=8) with limit of detection (LOD) of 1.5×10-3 mg L-1 (S/N=3) and limit of quantification (LOQ) of 5.0×10-3 mg L-1 (S/N=10). The relative standard deviation (RSD) was from 1.04-3.4% over the range studied and injection throughputs of 150 h-1. The method was satisfactorily applied to retinol in pharmaceutical formulation samples. The samples were saponified and extracted with liquid-liquid extraction using ether as an extractant. The possible CL mechanism is supported by CL and UV-visible spectrophotometric studies.

Bioinformatics analysis of ubiquitin expression protein gene from Heterodera latipons.

Ubiquitin expression protein DNA clone (Hl-UBI) was isolated from Heterodera latipons collected from North Jordan. Its sequence of 285 nucleotides was also determined and deposited in the GeneBank. The 285-bp open reading frame coded for 76-amino acid protein having two domains; the ubiquitin domain and the C terminal extension. The first 59 amino acids were predicted with the ubiquitin domain with identity percentages of 78% to ubiquitin of H. schachtii, 77% to polyubiquitin of Globodera pallida, 74% to ubiquitin of Globodera rostochiensis and 72% to ubiquitin of Heterodera glycines. The other domain at the C-terminus, containing 17 amino acids, showed no homology to any known protein. Sequence analysis showed a calculated encoding amino acids molecular weight of 8.77 kDa, theoretical isoelectric point = 4.76, negatively charged residues = 12, positively charged residues = 9, extinction coefficient = 1490, estimated half-life = 30 h, instability index = 32.51 and grand average of hydropathicity = -0.537. The demonstrated subcellular localization analysis of cytoplasm, cell nucleus, mitochondrion, cell skeleton and plasma membrane of Hl-UBI protein occupied about 52.20, 21.70, 17.40, 4.30 and 4.30%, respectively. Sequence, homology and structural analysis confirmed that Hl-UBI gene was highly conserved during evolution and belonged to ubiquitin gene family.

Comparative efficacy of different approaches to managing Meloidogyne incognita on green bean.

A greenhouse study was conducted to compare the relative efficacy of different approaches to managing Meloidogyne incognita on green bean. These approaches included chemical (fumigant, non-fumigant, seed dressing, and seed dip), biological (the egg-parasitic fungus, Paecilomyces lilacinus and the mycorrhizal fungus Glomus sp.), physical (soil solarization), and cultural (chicken litter and urea) methods. Accordingly, nine different control materials and application methods plus nematode-infected and non-infected controls were compared. Two important parameters were considered: plant response (plant growth and root galling) and nematode reproduction (production of eggs and the reproduction factor Rf). The results showed that the use of chicken litter as an organic fertilizer severely affected the growth and survival of the plants. Therefore, this treatment was removed from the evaluation test. All of the other eight treatments were found to be effective against nematode reproduction, but with different levels of efficacy. The eight treatments decreased (38.9-99.8%) root galling, increased plant growth and suppressed nematode reproduction. Based on three important criteria, namely, gall index (GI), egg mass index (EMI), and nematode reproduction factor (RF), the tested materials and methods were categorized into three groups according to their relative control efficacy under the applied test conditions. The three groups were as follows: (1) the relatively high effective group (GI = 1.0-1.4, Rf = 0.07-0.01), which included the fumigant dazomet, the non-fumigant fenamiphos, soil solarization, and seed dip with fenamiphos; (2) the relatively moderate effective group (GI = 3.4-4.0, Rf = 0.24-0.60), which included seed dressing with fenamiphos and urea; and (3) the relatively less effective group (GI = 5.0, Rf = 32.2-37.2), which included P. lilacinus and Glomus sp.