Reconstruction of the lipid metabolism for the microalga Monoraphidium neglectum from its genome sequence reveals characteristics suitable for biofuel production.

BACKGROUND: Microalgae are gaining importance as sustainable production hosts in the fields of biotechnology and bioenergy. A robust biomass accumulating strain of the genus Monoraphidium (SAG 48.87) was investigated in this work as a potential feedstock for biofuel production. The genome was sequenced, annotated, and key enzymes for triacylglycerol formation were elucidated. RESULTS: Monoraphidium neglectum was identified as an oleaginous species with favourable growth characteristics as well as a high potential for crude oil production, based on neutral lipid contents of approximately 21% (dry weight) under nitrogen starvation, composed of predominantly C18:1 and C16:0 fatty acids. Further characterization revealed growth in a relatively wide pH range and salt concentrations of up to 1.0% NaCl, in which the cells exhibited larger structures. This first full genome sequencing of a member of the Selenastraceae revealed a diploid, approximately 68 Mbp genome with a G + C content of 64.7%. The circular chloroplast genome was assembled to a 135,362 bp single contig, containing 67 protein-coding genes. The assembly of the mitochondrial genome resulted in two contigs with an approximate total size of 94 kb, the largest known mitochondrial genome within algae. 16,761 protein-coding genes were assigned to the nuclear genome. Comparison of gene sets with respect to functional categories revealed a higher gene number assigned to the category "carbohydrate metabolic process" and in "fatty acid biosynthetic process" in M. neglectum when compared to Chlamydomonas reinhardtii and Nannochloropsis gaditana, indicating a higher metabolic diversity for applications in carbohydrate conversions of biotechnological relevance. CONCLUSIONS: The genome of M. neglectum, as well as the metabolic reconstruction of crucial lipid pathways, provides new insights into the diversity of the lipid metabolism in microalgae. The results of this work provide a platform to encourage the development of this strain for biotechnological applications and production concepts.

Key considerations to inform operational EU-specific protection goals: An example for non-target terrestrial plants.

This paper complements recent considerations of specific protection goals (SPG) to inform risk assessments for non-target terrestrial plants (NTTP) in the European Union. The SPG options in-field appear to be of the most disruptive potential from agronomic perspective and are therefore investigated in more detail. Overarching prerequisites have been identified that need to be accounted for to ensure that any of the potential SPG options remain operational in a sustainable agricultural context. As soon as crop production is considered a desired ecosystem service for the in-field, its specific requirements in the context of sustainable agriculture have to be factored in. Good agricultural practices (GAPs), potential ecosystem disservices (e.g. weeds, pests and diseases) and supporting and regulating services need to be considered to ensure a successful and sustainable delivery of the ecosystem service crop production. Concerning in-field SPG options for NTTP specifically GAPs related to integrated weed management (IWM) require detailed assessment, as they individually and in combination have the purpose of weed control. Therefore, they result in specific implications to the environment, ecosystem services and biodiversity within the context of sustainable agricultural production. When diverging in-field ecosystem services are considered for the same context, the protection goals options require an additional assessment of synergies and trade-offs between the relevant ecosystem services (e.g. crop production, climate regulation and aesthetic values), a corresponding weighing and prioritization. Similarly, for biodiversity conservation, the trade-offs and synergies between sustainable crop production and specific habitat requirements need to be accounted for. Consequently, an interdisciplinary approach can ensure that SPG are operational by integrating a broad understanding of cropping systems, the environmental impact of the tools a farmer uses and the link between habitat availability, the impact of any of the applied tools on habitat quality and the broader landscape context. Integr Environ Assess Manag 2021;17:905-910. © 2021 Bayer AG, BASF SE and Syngenta. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Towards Integrated Pest and Pollinator Management in Intensive Pear Cultivation: A Case Study from Belgium.

Recently, the concept of Integrated Pest Management (IPM) was further extended into Integrated Pest and Pollinator Management (IPPM). Implementation of IPPM strategies entails the combination of actions for pest and pollinator management providing complementary or synergistic benefits for yield and/or quality of the harvest. The aim of this study was to examine IPPM elements (i.e., mixed hedgerow, nesting boxes for mason bees, Osmia spp.) and demonstrate their impact in the practical context of modern commercial fruit cultivation in a 4-year case study in an intensive 'Conference' pear orchard. The outcomes of visual observations during transect walks and molecular analysis of pollen collected by mason bees, showed the importance of additional floral resources for the presence of mason bees and other pollinating insects in the orchard environment. Pear quality assessments indicated that insect-mediated pollination had a significant positive impact, with a tendency for higher quality pears in the close vicinity of Osmia nesting boxes. However, despite the fact that pear pollen was also detected in Osmia spp. nest cells, the amount and frequency of pear pollen collection for their nest built-up turned out to be rather low. In the same intensive pear orchard studied for pollination effects, we simultaneously demonstrate the impact of a mixed hedgerow to enhance integrated pest control.

Identification of Monoraphidium contortum as a promising species for liquid biofuel production.

In this work, 30 microalgae strains from 17 genera were investigated in regard to biomass productivity in photoautotrophic growth conditions, lipid amount, lipid quality and biomass degradability. Six strains could be identified with robust phototrophic growth properties and high biomass productivities equal or above 300 mg l(-1) day(-1). Anaerobic fermentation of the algal biomass was most efficient for the marine members of the genera Dunaliella and Navicula, while biogas production with the freshwater strains generally resulted in lower methane yields. Monoraphidium contortum was identified as promising candidate for liquid biofuel production, characterized by high biomass productivity during maximum growth (maximum increase of 896 mg dry biomass weight (DW) l(-1) day(-1)) and a promising lipid profile. Neutral lipid production was strongly induced in M. contortum by nitrogen deficient conditions and accumulated to up to 20.4±2.2% of DW.