Biology subjects

Gerlach, R.

Publications and source records attributed to Gerlach, R..

4 recordsLinked to original sources

bioRxiv2025

Hunting for extremophiles: a systematic screening of freshwater microalgae for tolerance to high pH and high alkalinity cultivation

Microalgae hold the potential to supply sustainable food, fuel, plastics, and chemicals at commercial scales. Cultivating microalgae at extreme pH (>10) and high alkalinity provides multiple benefits including 1) reducing the risk of contamination by undesired organisms and 2) enabling direct air capture of CO2, which expands the land area suitable for algae farming compared to using CO2 point sources alone. However, we currently have a limited understanding of which algal taxa can grow under these conditions. Therefore, we conducted a high-throughput screening of 49 freshwater microalgae strains, comprising 40 species, for their ability to grow in moderate (pH 8.5, 25 mM alkalinity), high (pH 10, 75 mM alkalinity), and extreme (pH 10, 150 mM alkalinity) cultivation environments. Our results show that moderate alkalinity tends to significantly increase algae growth (including potentially harmful strains). However, higher levels inhibit all but a small subset of green algae and cyanobacteria. Effects of salinity and alkalinity differed, indicating they are broadly decoupled. Our results identify new industrially relevant alkaline-tolerant strains, show that algae isolated from "normal" ecosystems can be extremophilic, and suggest that future bioprospecting efforts for alkaline-tolerant algae adapted to local climatic conditions could yield additional productivity gains for the algae industry. SynopsisWe tested if 49 distinct microalgae strains could grow in high pH environments and found new and productive alkaline-tolerant strains Abstract/TOC Graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/676395v1_ufig1.gif" ALT="Figure 1"> View larger version (73K): org.highwire.dtl.DTLVardef@63d59dorg.highwire.dtl.DTLVardef@5d597eorg.highwire.dtl.DTLVardef@9e9be7org.highwire.dtl.DTLVardef@10d9160_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2024

Mycelium as a scaffold for biomineralized engineered living materials

Engineered living materials (ELMs) are garnering considerable attention as a promising alternative to traditional building materials because of their potentially lower carbon footprint and additional functionalities conferred by living cells. However, biomineralized ELMs designed for load-bearing purposes are limited in their current design and usage for several reasons, including (1) low microbial viability and (2) limited control of specimen internal microarchitecture. We created third generation biomineralized ELMs from fungal mycelium scaffolds that were mineralized either by the fungus itself or by ureolytic bacteria. Both self-mineralized (i.e. fungally-mineralized) and bacterially-mineralized scaffolds retained high microbial viability for at least four weeks in room temperature or accelerated dehydration storage conditions, without the addition of protectants against desiccation. The microscale modulus of calcium carbonate varied with the different biomineralized scaffold conditions, and moduli were largest and stiffest for bacterial biomineralization of fungal mycelium. As an example of how mycelium scaffolds can enable the design of complex internal geometries of biomineralized materials, osteonal-bone mimetic architectures were patterned from mycelium and mineralized using ureolytic bacteria. These results demonstrate the potential for mycelium scaffolds to enable new frontiers in the design of biomineralized ELMs with improved viability and structural complexity. Progress and PotentialBiomineralized engineered living materials (ELMs) offer new approaches for increasing the sustainability of building materials and processes. However, the design and usage of biomineralized ELMs is constrained by several important limitations, including low microbial viability and limited ability to control internal microarchitecture. Fungal mycelium scaffolds, biomineralized by either fungi or bacteria, achieve much higher viability of ureolytic microorganisms than what has been reported for biomineralized ELMs. Further, mycelium scaffolds permit the manufacturing of complex architectures, such as inspired by the structure of osteonal bone. Mycelium scaffolds have the potential to enable new frontiers in the design and use of biomineralized ELMs. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=71 SRC="FIGDIR/small/592484v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@338d98org.highwire.dtl.DTLVardef@94f956org.highwire.dtl.DTLVardef@7d8ed6org.highwire.dtl.DTLVardef@12cb61e_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2023

Pathology of natural infection with highly pathogenic avian influenza virus (H5N1) clade 2.3.4.4b in wild terrestrial mammals in the United States in 2022

This article describes the first detections of disease due to natural infection with highly pathogenic avian influenza virus (HPAIv) H5N1 of the Eurasian lineage goose/Guangdong clade 2.3.4.4b in wild terrestrial mammals throughout the United States during 2021-2022. Affected mammalian species include 50 red foxes (Vulpes vulpes), 6 striped skunks (Mephitis mephitis), 4 raccoons (Procyon lotor), 2 bobcats (Lynx rufus), 2 Virginia opossums (Didelphis virginiana), 1 coyote (Canis latrans), 1 fisher (Pekania pennanti), and 1 gray fox (Urocyon cinereoargenteus). Infected mammals primarily exhibited neurological signs. Necrotizing meningoencephalitis, interstitial pneumonia, and myocardial necrosis were the most common lesions; however, species variations in lesion distribution were observed. Genotype analysis of sequences from 48 animals indicates that these cases represent spillover infections from wild birds.

pathology↗

bioRxiv2021

Subsurface Hydrocarbon Degradation Strategies in Low- and High-Sulfate Coal Seam Communities Identified with Activity-Based Metagenomics

Environmentally relevant metagenomes and BONCAT-FACS derived translationally active metagenomes from Powder River Basin coal seams were investigated to elucidate potential genes and functional groups involved in hydrocarbon degradation to methane in coal seams with high- and low-sulfate levels. An advanced subsurface environmental sampler allowed the establishment of coal-associated microbial communities under in situ conditions for metagenomic analyses from environmental and translationally active populations. Metagenomic sequencing demonstrated that biosurfactants, aerobic dioxygenases, and anaerobic phenol degradation pathways were present in active populations across the sampled coal seams. In particular, results suggested the importance of anaerobic degradation pathways under high-sulfate conditions with an emphasis on fumarate addition. Under low-sulfate conditions, a mixture of both aerobic and anaerobic pathways were observed but with a predominance of aerobic dioxygenases. The putative low-molecular weight biosurfactant, lichysein, appeared to play a more important role compared to rhamnolipids. The methods used in this study--subsurface environmental samplers in combination with metagenomic sequencing of both total and translationally active metagenomes--offer a deeper and environmentally relevant perspective on community genetic potential from coal seams poised at different redox conditions broadening the understanding of degradation strategies for subsurface carbon. One Sentence SummaryIdentifying hydrocarbon degradation strategies across different redox conditions via metagenomic analysis of environmental and translationally active (BONCAT-FACS) samples from subsurface coal beds.

microbiology↗