Hydrogeochemical evolution processes, groundwater quality, and non-carcinogenic risk assessment of nitrate-enriched groundwater to human health in different seasons in the Hawler (Erbil) and Bnaslawa Urbans, Iraq.

The main objectives of this research are to assess groundwater, a primary source of drinking water in the urban areas of Hawler (Erbil) and Bnaslawa in northern Iraq, and the non-carcinogenic human health risks of nitrate contamination associated with drinking water quality. For this purpose, twenty-seven groundwater samples were collected from wells to assess the hydrogeochemical characteristics and groundwater quality for both natural and anthropogenic purposes during the wet (May 2020) and dry (September 2020) seasons. During the wet and dry seasons, NO3- in groundwater ranged from 14.00 to 61.00 mg/L and 12.00 to 60.00 mg/L, with an average value of 35.70 and 29.00 mg/L, respectively. Approximately 25.92% of the samples exceeded the permissible limit of the WHO (2011) drinking water standard. The ratios of NO3-/Na+ vs. Cl-/Na+ and SO42-/Na+ vs. NO3-/Na+ indicate the effect of agricultural activities and wastewater leaking from cesspools or septic tanks on the quality of groundwater during the wet and dry seasons. The entropy weighted water quality index method ranked 62.5% and 75% of the urban groundwater as not recommended for drinking, and the remaining samples are moderately suitable in both wet and dry seasons. The non-carcinogenic human health risk assessment displayed that during the wet and dry seasons, 29.6% and 25.9% of adults, 48% and 30% of children, and 48.1% and 29.6% of infants were exposed to increased concentrations of nitrate in groundwater. Due to high nitrate in drinking water, non-carcinogenic human health risk levels vary as infant > child > adults. The main findings obtained from this study can assist policymakers in better understanding the hydrogeochemical properties of groundwater in terms of drinking water safety, thereby facilitating the management of water resources to take the necessary measures.

Extracellular xylanase production by Fusarium species in solid state fermentation.

Fusarium sp. has been shown to be a promising organism for enhanced production of xylanases. In the present study, xylanase production by 21 Fusarium sp. isolates (8 Fusarium culmorum, 4 Fusarium solani, 6 Fusarium verticillioides and 3 Fusarium equiseti) was evaluated under solid state fermentation (SSF). The fungal isolate Fusarium solani SYRN7 was the best xylanase producer among the tested isolates. The effects of some agriculture wastes (like wheat straw, wheat bran, beet pulp and cotton seed cake) and incubation period on xylanase production by F. solani were optimized. High xylanase production (1465.8 U/g) was observed in wheat bran after 96 h of incubation. Optimum pH and temperature for xylanase activity were found to be 5 and 50 degrees C, respectively.

Efficiency of IRAP and ITS-RFLP marker systems in accessing genetic variation of Pyrenophora graminea.

The usefulness of IRAP (inter-retrotransposon amplified polymorphism) and ITS-RFLP (restriction of PCR-amplified internal transcribed spacers of the rDNA) markers in the analysis of 39 Pyrenophora graminea isolates was determined. Each marker system could discriminate between all of the isolates in detecting polymorphism, albeit with variable efficiency. IRAP and ITS-RFLP produced 85% and 77% polymorphic bands, respectively, with a corresponding mean polymorphic information content (PIC) of 0.38 and 0.36. The IRAP marker index ratio (2.41) was higher than ITS-RFLP (1.50). On one hand, the quality nature of data (QND) was higher for ITS-RFLP (0.169) than IRAP (0.093). However, correlation between both marker similarity matrices was significant (r = 0.34, p < 0.05). These findings suggest their combined use in phylogenetic analysis. To our knowledge, this is the first report of a comparison involving these two advanced DNA marker systems.

Efficiency of IRAP and ITS-RFLP marker systems in accessing genetic variation of Pyrenophora graminea

The usefulness of IRAP (inter-retrotransposon amplified polymorphism) and ITS-RFLP (restriction of PCR-amplified internal transcribed spacers of the rDNA) markers in the analysis of 39 Pyrenophora graminea isolates was determined. Each marker system could discriminate between all of the isolates in detecting polymorphism, albeit with variable efficiency. IRAP and ITS-RFLP produced 85 percent and 77 percent polymorphic bands, respectively, with a corresponding mean polymorphic information content (PIC) of 0.38 and 0.36. The IRAP marker index ratio (2.41) was higher than ITS-RFLP (1.50). On one hand, the quality nature of data (QND) was higher for ITS-RFLP (0.169) than IRAP (0.093). However, correlation between both marker similarity matrices was significant (r = 0.34, p < 0.05). These findings suggest their combined use in phylogenetic analysis. To our knowledge, this is the first report of a comparison involving these two advanced DNA marker systems.

Improvement of xylanase production by Cochliobolus sativus in solid state fermentation / Melhoramento da produção de xilanase por Cochliobolus sativus por fermentação em estado sólido

The xylanase production by Cochliobolus sativus strain Cs6 was improved under solid state fermentation (SSF). High xylanase activity (1079 U/g) was obtained when wheat straw was used after 8 days of incubation. Combinations of sodium nitrate with peptone or yeast extract resulted in an increased xylanase production (1543 and 1483 U/g, respectively). The Cs6 strain grown in SSF in a simple medium, proved to be a promising microorganism for xylanase production.

A produção de xilanase por Cochliobolus sativus cepa Cs6 SATIVUS por fermentação em estado sólido (SSF) foi melhorada. Com o emprego de palha de trigo, obteve-se elevada atividade de xilanase (1079 U/g) após 8 dias de incubação. Combinações de nitrato de sódio com peptona ou extrato de levedura aumentaram a produção de xilanase (1543 e 1483 U/g, respectivamente). Comprovou-se que a cepa Cs6, cultivada em SSF em meio simples, é um microrganismo promissor para produção de xilanase.

Polymorphism in the ITS region of ribosomal DNA of Cochliobolus sativus isolates differing in xylanase production.

The restriction of PCR-amplified internal transcribed spacers (ITS) ofribosomal DNA was used to confirm the genetic variation among 22 isolates of Cochliobolus sativus differing in their xylanase production. Results show a high level of diversity of ITS-RFLP markers among the isolates. The molecular parameter used showed that C. sativus isolates reside in three phylogenetic groups. There was observed the resolution between clustering of isolates and their xylanase production level.

Improvement of xylanase production by Cochliobolus sativus in solid state fermentation.

The xylanase production by Cochliobolus sativus strain Cs6 was improved under solid state fermentation (SSF). High xylanase activity (1079 U/g) was obtained when wheat straw was used after 8 days of incubation. Combinations of sodium nitrate with peptone or yeast extract resulted in an increased xylanase production (1543 and 1483 U/g, respectively). The Cs6 strain grown in SSF in a simple medium, proved to be a promising microorganism for xylanase production.

RAPD technique is a useful tool to distinguish Penicillium species.

Random amplified polymorphic DNA (RAPD) analysis was used to evaluate genetic diversity among 13 soil Penicillium strains originating from widely dispersed areas. Twenty one of the 34 synthetic random primers were found to identify polymorphism in amplification products. The results show a high level of diversity of RAPD markers among the strains. All the strains could be identified by their characteristic amplification profile, using selected random primers. This suggests that RAPD analysis is a useful and reliable assay for characterizing the species of Penicillium genus.