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Climate change is the most serious challenge facing humanity. Microbes produce and consume three major greenhouse gases-carbon dioxide, methane, and nitrous oxide-and some microbes cause human, animal, and plant diseases that can be exacerbated by climate change. Hence, microbial research is needed to help ameliorate the warming trajectory and cascading effects resulting from heat, drought, and severe storms. We present a brief summary of what is known about microbial responses to climate change in three major ecosystems: terrestrial, ocean, and urban. We also offer suggestions for new research directions to reduce microbial greenhouse gases and mitigate the pathogenic impacts of microbes. These include performing more controlled studies on the climate impact on microbial processes, system interdependencies, and responses to human interventions, using microbes and their carbon and nitrogen transformations for useful stable products, improving microbial process data for climate models, and taking the One Health approach to study microbes and climate change.

Soil surface consortia are easily observed and sampled, allowing examination of their interactions with soil microbiomes. Here, we present metatranscriptomic sequences from Dark Green 1 (DG1), a cyanobacterium-based soil surface consortium, in the presence and absence of an underlying soil microbiome and/or urea.

From 1913 to 1980, two zinc smelters in Palmerton, Pennsylvania, emitted large quantities of atmospheric pollutants nearly eliminating forests along a ridge above the town. In 2008, a remediation treatment was applied to the land above one of the smelters that included the planting of several locally adapted plant species. It also included mineral fertilization and mycorrhizal inoculation. One of the species, the Pitch pine (Pinus rigida, Mill.), is a native tree that is both tolerant of metalliferous soils and obligatorily ectomycorrhizal. This report summarizes the results of two observational studies conducted 5 years after the remediation treatment. The first study's objective was to compare ectomycorrhizal communities on treated Pitch pine saplings, with communities on naturally regenerating saplings in an adjacent non‐remediated area. The second study's objective was to determine if the composition of the fungal communities on root tips of naturally regenerating Pitch pine saplings differed with distance from the smelters. Fungal community compositions were determined using internal transcribed spacer rRNA sequences. Comparisons of sequences from the remediated and non‐remediated sites revealed that communities at the remediated sites had lower taxonomic diversity and were dominated by members of a genus in the remediation inoculant. The results of the smelter‐proximity study indicated that although fungal diversity did not differ markedly with distance from the smelters, the relative abundances of some taxa were greater on saplings growing directly above the smelters, where the soils contained highest concentrations of zinc and cadmium. [ABSTRACT FROM AUTHOR]

The early years of soil genesis during mine spoil reclamation are critical for vegetative establishment and may help predict reclamation success. Mine spoils in the Halle-Leipzig region of Germany were analyzed for microbial changes following a hay mulch-seeding treatment without topsoil or fertilizer application. Microbial biomass carbon ([C.sub.mic]) and dehydrogenase activity (DHA) of spoils were measured each year in the first 3 yr alter treatment. In the third year, bacterial community DNA fingerprints were compared with those from a reference soil. Microbial indicators were measured at three depths in the upper 10 cm of spoils at three sites with contrasting parent materials: glacial till (sandy loam), limnic tertiary sediments (high-lignite sandy clay loam), and quaternary sand and gravel (loamy sand). Before reclamation, [C.sub.mic] means and standard deviations of surface spoils (0-1 cm) were 9 [+ or -] 6, 39 [+ or -] 11, and 38 [+ or -] 16 mg [kg.sup.-1] for the loamy sand, high-lignite sandy clay loam, and sandy loam spoils, respectively. Within one year, mean [C.sub.mic] at the surface increased to 148 [+ or -] 70, 229 [+ or -] 64, and 497 [+ or -] 167 mg [kg.sup.-1], respectively, and was significantly higher at 0 to 1 cm than at lower depths. Highest DHA and DNA yields were obtained in the 0- to 1-cm depth of the sandy loam spoils. Microbial biomass C values exhibited significant correlations with DHA, DNA yield, and extractable C for all three mine spoils. Soil microbial indices were more responsive than plant measurements to differences in parent materials.

Chemical species that are biologically derived, and associated with a particular crop in a farming area, can be more helpful in discriminating soil samples.

A study was conducted to compare the autotrophic ammonia oxidizer population structures in long-term ecological research soils using polymerase chain reaction amplification of microbial community DNA with primers specific for 16S rRNA genes. The comparative study was done to assess the effects of disturbance on certain soil bacteria. Findings revealed that tilled soils contained higher population sizes than native culturable soils.

Research was conducted to examine the influence of soil pH on the compositions of natural populations of autotrophic beta-subroup proteobacterial ammonia oxidizers. A combination of oligonucleotide probing and denaturing gradient gel electrophoresis (DGGE) was used with objective of investigating the hypotheses that Nitrosospira may be significant for ammonia oxidation in acid soils and that the relative abundances of various sequence clusters are related to soil pH. Results reveal the value of DGGE and suggests that Nitrosospira cluster 2 may be important for ammonia-oxidizing activity in acid soils.

The sodium dodecyl sulfate (SDS) method of bacterial DNA extraction from soils is simple, quick and efficient. The method involves bacterial lysis with a high-salt extraction buffer, followed by the heating of the soil suspension with SDS, hexadecyltrimethylammonium bromide and proteinase K. A combination of SDS with grinding and freezing-thawing increases the DNA extraction efficiency. The best DNA purification method is the gel-plus-minicolumn method. The gel-plus-concentration method gives the highest DNA recovery rate.

The results from performance analysis of a single-chamber microbial fuel cell (MFC) to remove chemical odors from swine wastewater are presented. The results indicated that MFCs made it possible not only to accelerate the rate of odor removal, but was also found to be effective in removing organic matter and producing electricity.

A novel approach to swine waste odor reduction is investigated in the form of the addition of FeCl3, a commonly used coagulant in municipal wastewater treatment, to stimulate degradation of odorous compounds by dissimilatory iron-reducing bacteria (DIRB). DNA sequences obtained from rRNA gene amplicons of bacterial communities in FeCl3-treated microcosms were closely related to Desulfitobacterium spp., which are known representatives of DIRB.