​​The utilisation of Antarctic microalgae isolated from Paradise Bay (Antarctic Peninsula) in the bioremediation of diesel

Research has confirmed that the utilisation of Antarctic microorganisms, such as bacteria, yeasts and fungi, in the bioremediation of diesel may provide practical alternative approaches. However, to date there has been very little attention towards Antarctic microalgae as potential hydrocarbon degraders. Therefore, this study focused on the utilisation of an Antarctic microalga in the bioremediation of diesel. The studied microalgal strain was originally obtained from a freshwater ecosystem in Paradise Bay, western Antarctic Peninsula. When analysed in systems with and without aeration, this microalgal strain achieved a higher growth rate under aeration. To maintain the growth of this microalga optimally, a conventional one-factor-at a-time (OFAT) analysis was also conducted. Based on the optimized parameters, algal growth and diesel degradation performance was highest at pH 7.5 with 0.5 mg/L NaCl concentration and 0.5 g/L of NaNO3 as a nitrogen source. This currently unidentified microalga flourished in the presence of diesel, with maximum algal cell numbers on day 7 of incubation in the presence of 1% v/v diesel. Chlorophyll a, b and carotenoid contents of the culture were greatest on day 9 of incubation. The diesel degradation achieved was 64.5% of the original concentration after 9 days. Gas chromatography analysis showed the complete mineralisation of C7–C13 hydrocarbon chains. Fourier transform infrared spectroscopy analysis confirmed that strain WCY_AQ5_3 fully degraded the hydrocarbon with bioabsorption of the products. Morphological and molecular analyses suggested that this spherical, single-celled green microalga was a member of the genus Micractinium. The data obtained confirm that this microalga is a suitable candidate for further research into the degradation of diesel in Antarctica

Harnessing Diesel-Degrading Potential of an Antarctic Microalga from Greenwich Island and Its Physiological Adaptation

Phytoremediation is a plant-based approach to extract, stabilise, eliminate, or render pollutants into less harmful form. The study highlights the use of a native polar microalga as a means of phytoremediation in Antarctica where imported microbes are prohibited. Since 1959, Antarctica has been a protected region to preserve its dynamic ecosystems, but it is increasingly vulnerable to climate change and pollution. One of the anthropogenic disturbances in the continent is diesel spillage. Due to the extreme polar environment, natural attenuation of spilled diesel is severely hindered; hence, the problem calls for an effective and sustainable solution. This laboratory study proved that Antarctic microalga was capable of removing diesel (57.6%) through biodegradation and biosorption in the span of nine days. Meanwhile, mixotrophic cultivation triggered the vacuolar activities and potentially stimulated lipid assimilation in the cells. The microalgal-based process offers a cheap alternative in water decontamination while bearing the economic potential through the secretion of valuable products, such as biolipids

Bibliometric Analysis of Research on Diesel Pollution in Antarctica and a Review on Remediation Techniques

Diesel is a fuel commonly used in Antarctica to supply vessels and domestic applications on site. The increasing human activities in the continent consequently have generated high fuel demand, which in turn has increased the occurrence of oil pollution due to accidental events during refueling. A related study received growing interest as more detrimental effects have been reported on Antarctic ecosystems. By adopting the bibliometric analysis, the research on diesel pollution in Antarctica collected in the Scopus database was systematically analysed. An increment in annual publication growth from 1980 to 2019 was observed and two research clusters were illustrated with “hydrocarbons” as the core keyword. Several attempts have been conducted over the past decades to remove anthropogenic hydrocarbon from previous abandoned whaling sites as well as recent oil spill incidents. However, the remote and polar conditions of Antarctica constrained the installation and operation of clean-up infrastructure. This review also briefly encompasses the approaches from past to present on the management of fuel pollution in Antarctica and highlights the potential of phytoremediation as a new bioremediation prospect

Methods for monitoring outdoor recreation and tourism in large nature areas

I detta Working Paper diskuteras kunskapsbehovet av friluftsliv och turism inom fysisk planering i den svenska fjällregionen. Artikeln diskuterar datainsamling och presenterar olika metoder.   En fallstudie bland besökarna i Södra Jämtlandsfjällen presenteras med fokus på de använda metoderna.   Studien genomfördes som en del av den fördjupade översiktsplanen som Åre och Bergs kommuner jobbade tillsammans med. De centrala frågorna handlade om naturskydd, förvaltning av friluftsliv, ekonomisk utveckling och resurskonflikter. Redan i början av processen upptäcktes brister i kunskap om turism och friluftsliv av några av de centrala aktörerna. Detta resulterade i den studie som beskrivs och diskuteras i den här artikeln.   Den ursprungliga tanken om att ha den producerade kunskapens roll i planeringsprocessen som central fråga i den här artikeln gjordes omöjligt av det faktumet att planeringsprocessen stoppades relativt tidigt när de olika parterna inte kunde hitta konsensus kring de viktigaste frågorna.   Däremot har man studerat och diskuterat erfarenheterna av de olika metoderna och använt en ekostrategisk modell för att analysera och diskutera kunskapens legitimitet och förhållandet mellan de olika landskapsperspektiven och det upplevda kunskapsbehovet.   Studien är skriven på engelska.  

A review and bibliometric analysis on applications of microbial degradation of hydrocarbon contaminants in arctic marine environment at metagenomic and enzymatic levels

The globe is presently reliant on natural resources, fossil fuels, and crude oil to support the world’s energy requirements. Human exploration for oil resources is always associated with irreversible effects. Primary sources of hydrocarbon pollution are instigated through oil exploration, extraction, and transportation in the Arctic region. To address the state of pollution, it is necessary to understand the mechanisms and processes of the bioremediation of hydrocarbons. The application of various microbial communities originated from the Arctic can provide a better interpretation on the mechanisms of specific microbes in the biodegradation process. The composition of oil and consequences of hydrocarbon pollutants to the various marine environments are also discussed in this paper. An overview of emerging trends on literature or research publications published in the last decade was compiled via bibliometric analysis in relation to the topic of interest, which is the microbial community present in the Arctic and Antarctic marine environments. This review also presents the hydrocarbon-degrading microbial community present in the Arctic, biodegradation metabolic pathways (enzymatic level), and capacity of microbial degradation from the perspective of metagenomics. The limitations are stated and recommendations are proposed for future research prospects on biodegradation of oil contaminants by microbial community at the low temperature regions of the Arctic

Growth and photosynthesis of Chlorella strains from polar, temperate and tropical freshwater environments under temperature stress

Elevated temperatures as a consequence of global warming have significant impacts on the adaptation and survival of microalgae which are important primary producers in many ecosystems. The impact of temperature on the photosynthesis of microalgae is of great interest as the primary production of algal biomass is strongly dependent on the photosynthetic rates in a dynamic environment. Here, we examine the effects of elevated temperature on Chlorella strains originating from different latitudes, namely Antarctic, Arctic, temperate and tropical regions. Chlorophyll fluorescence was used to assess the photosynthetic responses of the microalgae. Rapid light curves (RLCs) and maximum quantum yield (F v / F m ) were recorded. The results showed that Chlorella originating from different latitudes portrayed different growth trends and photosynthetic performance. The Chlorella genus is eurythermal, with a broad temperature tolerance range, but with strain-specific characteristics. However, there was a large overlap between the tolerance range of the four strains due to their “eurythermal adaptivity”. Changes in the photosynthetic parameters indicated temperature stress. The ability of the four strains to reactivate photosynthesis after inhibition of photosynthesis under high temperatures was also studied. The Chlorella strains were shown to recover in terms of photosynthesis and growth (measured as Chl a) when they were returned to their ambient temperatures. Polar strains showed faster recovery in their optimal temperature compared to that under the ambient temperature from which they were isolated

Combined effects of glufosinate ammonium and temperature on the growth, photosynthetic pigment content and oxidative stress response of Chlorella sp. and Pseudokirchneriella subcapitata

There has been concern over the potential adverse effects of glufosinate ammonium, a widely used herbicide, on microalgae. This study aimed to assess the combined effects of glufosinate and temperature on Chlorella sp. CHSS262, which was isolated from a farmland in Malaysia, in comparison with the model microalga Pseudokirchneriella subcapitata. The following parameters were assessed: growth, pigment content and oxidative stress response. Results showed that Chlorella sp. (EC25 = 120 μg mL−1) was more tolerant to glufosinate than P. subcapitata (EC25 = 43 μg mL−1) when grown at 28 °C. Both microalgae were then exposed to glufosinate at EC25 at different temperatures (10, 18, 28, 33 and 38 °C) for 8 days. While P. subcapitata could grow from 10 to 38 °C, with optimal temperature between 18 and 28 °C, the lower temperature limit of Chlorella sp. was 18 °C. There was only minimal growth inhibitory effect of glufosinate on Chlorella sp. over the range of temperatures tested. In comparison, the inhibitory effect of glufosinate on P. subcapitata was less pronounced at extreme temperatures (10 and 38 °C) compared to that at 18 to 33 °C. High ROS levels and increased lipid peroxidation were detected in P. subcapitata at 10 and 38 °C in both the control and glufosinate-treated cultures. Principal component analysis (PCA) showed that there was significant correlation between ROS and lipid peroxidation in P. subcapitata but not in Chlorella sp. Overall, the results showed that Chlorella sp. and P. subcapitata responded differently to temperature and glufosinate, especially in regard to oxidative stress response although both species were highly resistant to the herbicide

Percentage inhibition, by PAR + UV-A + UV-B, of (a) rETR_max and (b) alpha for all three isolates of <i>Chlorella</i>.

<p>Vertical bars denote standard deviations from triplicate samples.</p

Inhibition of light harvesting efficiency (alpha) and maximal electron transport rate (rETR_max) of polar, temperate and tropical <i>Chlorella</i> grown at their optimum temperatures (18, 20 and 30°C, respectively) then exposed to PAR + UV-A + UV-B for 60 min.

<p>Vertical bars denote standard deviations from triplicate samples.</p

Effect of temperature and UVR on the maximum quantum yield of fluorescence (ΦPSII_max) of (a) polar, (b) temperate and (c) tropical isolates of <i>Chlorella</i>.

<p>Vertical bars denote standard deviations from triplicate samples. Different letters indicate significant differences at p<0.05. PAR (filled), PAR + UV-A (open), PAR + UV-A + UV-B (hatched).</p