16S ribosomal RNA gene (rDNA) amplicon analysis remains the standard approach for the cultivation-independent investigation of microbial diversity. The accuracy of these analyses depends strongly on the choice of primers. The overall coverage and phylum spectrum of 175 primers and 512 primer pairs were evaluated in silico with respect to the SILVA 16S/18S rDNA non-redundant reference dataset (SSURef 108 NR). Based on this evaluation a selection of 'best available' primer pairs for Bacteria and Archaea for three amplicon size classes (100-400, 400-1000, ≥ 1000 bp) is provided. The most promising bacterial primer pair (S-D-Bact-0341-b-S-17/S-D-Bact-0785-a-A-21), with an amplicon size of 464 bp, was experimentally evaluated by comparing the taxonomic distribution of the 16S rDNA amplicons with 16S rDNA fragments from directly sequenced metagenomes. The results of this study may be used as a guideline for selecting primer pairs with the best overall coverage and phylum spectrum for specific applications, therefore reducing the bias in PCR-based microbial diversity studies.

Evaluation of general 16S ribosomal RNA gene PCR primers for classical and next-generation sequencing-based diversity studies

Fouling in membrane bioreactors used in wastewater treatment

Physico-chemical treatment techniques for wastewater laden with heavy metals

Recent advances in membrane bioreactors (MBRs): membrane fouling and membrane material.

We report the design and evaluation of PCR primers 63f and 1387r for amplification of 16S rRNA genes from bacteria. Their specificity and efficacy were tested systematically with a variety of bacterial species and environmental samples. They were found to be more useful for 16S rRNA gene amplification in ecological and systematic studies than PCR amplimers that are currently more generally used.

Design and Evaluation of Useful Bacterium-Specific PCR Primers That Amplify Genes Coding for Bacterial 16S rRNA

In this paper, we describe a culture-based biochip for detecting microorganisms in environmental samples in an improved, timesaving, and cost-efficient manner. The biochips use the paraffinophilic nature of microorganisms to rapidly detect and differentiate them in sewage samples collected from wastewater treatment plants. A new method of depositing paraffin was developed in order to fabricate such biochips. The developed technique uses butanol solvent to keep paraffin liquid during deposition by spin-coating and thick photoresist for patterning. Using this approach, 18 mm glass biochips with paraffin layers of 5-70 /spl mu/m have been successfully fabricated. These biochips were used to demonstrate rapid, 5-min detection of microorganisms responsible for reactor foaming in wastewater treatment.

Developing culture-based biochips for detecting microorganisms in wastewater treatment

Improving Interprofessional Environmental Health Education Using the Leave No One Behind Framework.

To uncover the experiences of parenting Generation Z pre-teen children in rural communities impacted by the Stay Home Missouri order from April through May 2020. Researchers have focused on urban parents, leading to gaps in understanding the impact of the COVID-19 quarantine on rural parents and children. A qualitative study employing interpretive phenomenology. 14 white cis-male-sexed fathers and cis-female-sexed mothers living in midwestern rural communities participated in this study. Semi-structured interviews with 14 participants parenting pre-teen children were conducted. The interviews were analyzed using interpretive phenomenology. The COREQ checklist was followed. One theme that emerged from the narratives was the study participants' understandings of parenting, discovered when their routines were disrupted by the Stay Home Missouri order. This theme involved three sub-themes: 1) responding to the challenges of protecting pre-teen children; 2) coping with disrupted social relationships; and 3) renegotiating responsibilities. Professionals who work with families need to find ways to assist parents during and after a health emergency that requires quarantine. COVID-19 is not the first pandemic to endanger humanity, and the next pandemic-or a future variant of SARS-could require an additional period of local, regional, or national quarantine. Implications for professionals supporting parents during periods of severe disruption-such as future public health crises as well as large scale quarantines-are offered to assist with preparation for and coping with severe disruptions to parenting.The online version contains supplementary material available at 10.1007/s40653-022-00507-9. 

/pdf/parenting-pre-teens-during-covid-19-in-a-rural-midwestern-491gqk9p.pdf

Parenting Pre-teens During COVID-19 in a Rural Midwestern Community: An Interpretive Phenomenological Study

A laboratory-scale reactor study was conducted to evaluate the potential for biomass input to stabilize nitrification at low temperatures and allow shorter solids retention times. Recovery and enrichment of nitrifying microorganisms in a second-sludge side-stream reactor treating anaerobic digester supernatant in batch and continuously-fed configurations was evaluated. Complete oxidation of ammonia to nitrate was observed in all main-stream reactors, as expected, during the initial phase of the experiment conducted at room temperature. However, as temperature was reduced to 10°C nitrite accumulation was experienced in all reactors. Incomplete ammonia oxidation has also been experienced to a lesser extent. However, it appears that input of biomass from a batch-fed side-stream reactor to a batch-fed main-stream reactor is more beneficial to nitrification stability than input from a continuously-fed side-stream. The side-stream reactors have experienced upsets brought on by operator error resulting in nitrite accumulation likely due to reduced oxygen tension. A potential mechanism involves accumulation of free hydroxylamine.

http://environmental-expert.com/files\5306\articles\8885\126.pdf

Daniel B. Oerther

Papers

Developing culture-based biochips for detecting microorganisms in wastewater treatment

Improving Interprofessional Environmental Health Education Using the Leave No One Behind Framework.

Parenting Pre-teens During COVID-19 in a Rural Midwestern Community: An Interpretive Phenomenological Study

Efficacy of biomass input into main-stream treatment from warm sludge liquor treatment at cold temperatures

Using Genomics to Understand Disinfection with Silver