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Petroleum derived plastics are a major contributor to global pollution. There is an urgent need for biodegradable, sustainable plastic alternatives. Cyanobacteria have been studied extensively for photosynthetic production of biofuel precursors including alkanes and free fatty acids. However, large scale production has been slow to emerge from these technologies. Here, we wished to evaluate alternative uses for engineered strains of the cyanobacteria Synechocystis PCC 6803 (6803). We investigated the feasibility of using wild type and fatty acid secreting strains of 6803 to support the growth of Ralstonia eutropha. This organism is capable of producing polyhydroxyalkanoates (PHAs), which can be used in bioplastic production. Traditional feedstocks for R. eutropha include palm oil and other biological precursors that compete with cultivatable land, pitting potential bioplastic production against agricultural demands. Since PHAs are of great interest as plastic alternatives, we co-cultured R. eutropha and 6803 strains in the minimal medium BG-11 in an attempt to create carbon neutral PHA from R. eutropha. Surprisingly, we observed inhibition of R. eutropha growth in co-culture with Synechocystis but not another cyanobacterium suggesting further modification of Synechocystis is necessary for use as a feedstock.

As a fully aquatic mammal, the Florida manatee (Trichechus manatus latirostris) spends a limited amount of time at the water's surface. However, as a mammal that breathes air, they do need to filter, warm, and humidify that air, and anecdotal evidence indicates manatees have a sense of smell. This study characterized the nasal turbinate system, including identification of the olfactory epithelium, and compared it to other mammals using a combination of gross and micro-anatomic examination. Major turbinates were present, including nasal, maxillary, and ethmoturbinates, but with minimal convolution. The respiratory epithelium was found throughout much of the nasal cavity and covered maxillary and nasal turbinates, as well as the septum. Mucus-producing cells and cavernous veins were extensive. The olfactory epithelium was found in the dorsocaudal ethmoturbinates. As a herbivore that feeds predominantly underwater, the manatee likely relies on taste and touch for assessing food and, therefore, does not need to use smell in the same way as other marine mammals such as mysticetes (Bouchard et al., 2019) and pinnipeds (Kowalewsky et al., 2006). However, there are still substantial numbers of olfactory cells, especially considering the decreased amount of exposure time to odorants when breathing at the surface. Therefore, the question remains of why manatees have maintained their ability to smell while other fully aquatic species such as odontocetes have not. Future research should focus on a combination of behavioral and molecular techniques to fully understand the olfactory capabilities of the Florida manatee. © 2020, European Association for Aquatic Mammals.

Vineyards in the New England region of the USA were surveyed for the occurrence of grapevine viruses. A total of ten vineyards were visited and 62 composite samples of leaves with the petioles were collected from symptomatic grapevines (Vitis spp.). All of the samples were assayed by double-antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISA) using antibodies specific for four major grapevine leafroll-associated viruses (GLRaV-1, GLRaV-2, GLRaV-3, and GLRaV-4), grapevine fanleaf virus (GFLV), tobacco ringspot virus (TRSV), and tomato ringspot virus (ToRSV). Positive ELISA samples were further tested by reverse transcription polymerase chain reaction (RT-PCR) with primers specific for each of the viruses to confirm the ELISA results. Twenty-two samples were infected with at least one of the viruses tested. GLRaV-3 (24.19%) was the most prevalent virus detected followed by GLRaV-1 (12.90%), ToRSV (3.23%), and GLRaV-2 and TRSV (1.61%). This is the first study reporting on the presence of grapevine viruses in New England. Extensive surveys need to be conducted to evaluate the prevalence and economic impact of these viruses on New England vineyards. © 2020 Elsevier Ltd

Recent work in Australia and Africa has shown that heterothermy is widespread among phylogenetically diverse tropical and subtropical mammalian taxa. However, data on the use of heterothermy by Neotropical mammals are relatively scant, and those studies that exist focus on insect-eating bats. We investigated the capacity of fruit-eating Neotropical bats to use heterothermy when exposed to acute cold temperatures, and compared this to previous data focused on insect-eating bats sampled from the same region and time of year. We measured rectal temperatures prior to acute cold exposure (1 hr at an air temperature of 6, 7, or 10°C), and again after exposure. Our data show considerable variation in the thermoregulatory patterns of Neotropical bats, and generally, our results show that smaller bats cool quicker and to a greater extent than larger bats. Our results highlight the importance of energy conservation even in environments in which resources are relatively abundant. © 2020 The Association for Tropical Biology and Conservation

The Florida manatee, Trichechus manatus latirostris, is a fully aquatic, threatened marine mammal for which increased understanding of their physiology, reproduction, and nutrition supports management decisions. Manatees may use taste to distinguish saltwater gradients, toxin detection, food assessment, and social interactions. This study sought to locate and characterize manatee taste buds comparing location, structure, number, and size to other species. Entire heads from manatees (6 males, 4 females) of various ages were obtained. The muzzle, tissue surrounding the nares, oral cavity, and epiglottis were examined grossly for pits and papillae. Tissues were examined using light and transmission electron microscopy. Within the predominant taste bud location, the tongue root, taste bud number was estimated using samples from four animals. The average number of taste buds within the tongue root was 11,534 (range 2,711–23,237) with sparse taste buds located on the soft palate and epiglottis. The location along the lateral surface of the tongue root and bordered by grooves, through which tastants could be easily transported, has functional significance. Large numbers of taste buds within the tongue root suggest that taste is an important component of manatee sensory systems and behavioral research would clarify this. © 2020 Society for Marine Mammalogy

Extreme climatic events including marine heatwaves (MHWs) are becoming more frequent and severe in the Anthropocene. However, our understanding of how these events affect population dynamics of ecologically important species is limited, in part because extreme events are rare and difficult to predict. Here, we quantified the occurrence and severity of MHWs over 60 years in warm range edge kelp forests on both sides of the North Atlantic. The cumulative annual intensity of MHWs increased two- to four-fold during this period, coinciding with the disappearance of kelps. We experimentally demonstrated a relationship between strong and severe 2018 heatwaves and high kelp mortality in both regions. Patterns of kelp mortality were strongly linked to maximum temperature anomalies, which crossed lethal thresholds in both regions. Translocation and tagging experiments revealed similar kelp mortality rates on reefs dominated by healthy kelp forests and degraded sediment-laden algal ‘turfs’, indicating equal vulnerability to extreme events. These results suggest a mechanistic link between MHWs and broad-scale kelp loss, and highlight how warming can make ecosystem boundaries unstable, forcing shifts to undesirable ecosystem states under episodically extreme climatic conditions. © 2020, The Author(s).

Environmental enrichment (EE) is one experimental manipulation that induces changes in the brain. However, it is important to distinguish between physical and social components of enrichment. To this end we established four groups of rats reared in different enriched environments during the adolescent period. Our results indicate heightened social memory and increased spine density in dentate gyrus specifically in socially enriched animals. Physical enrichment increased spine density in CA1. Dopamine D2 receptor expression in hippocampus was decreased across all enrichment conditions. Altogether, our results demonstrate differing effects of physical and social enrichment, supporting an important role for environment in synaptogenesis, behavior, and dopaminergic signaling. © 2020 The Authors

The bacteriophage population is vast, dynamic, old, and genetically diverse. The genomics of phages that infect bacterial hosts in the phylum Actinobacteria show them to not only be diverse but also pervasively mosaic, and replete with genes of unknown function. To further explore this broad group of bacteriophages, we describe here the isolation and genomic characterization of 116 phages that infect Microbacterium spp. Most of the phages are lytic, and can be grouped into twelve clusters according to their overall relatedness; seven of the phages are singletons with no close relatives. Genome sizes vary from 17.3 kbp to 97.7 kbp, and their G+C% content ranges from 51.4% to 71.4%, compared to ~67% for their Microbacterium hosts. The phages were isolated on five different Microbacterium species, but typically do not efficiently infect strains beyond the one on which they were isolated. These Microbacterium phages contain many novel features, including very large viral genes (13.5 kbp) and unusual fusions of structural proteins, including a fusion of VIP2 toxin and a MuF-like protein into a single gene. These phages and their genetic components such as integration systems, recombineering tools, and phage-mediated delivery systems, will be useful resources for advancing Microbacterium genetics.