Microbial community profiles of recently formed hot spring systems ranging in temperatures from 57°C to 100°C and pH values from 2 to 4 in Hveragerði (Iceland) were analyzed with PhyloChip G3 technology. In total, 1173 bacterial operational taxonomic units (OTUs) spanning 576 subfamilies and 38 archaeal OTUs covering 32 subfamilies were observed. As expected, the hyperthermophilic (∼100°C) spring system exhibited both low microbial biomass and diversity when compared to thermophilic (∼60°C) springs. Ordination analysis revealed distinct bacterial and archaeal diversity in geographically distinct hot springs. Slight variations in temperature (from 57°C to 64°C) within the interconnected pools led to a marked fluctuation in microbial abundance and diversity. Correlation and PERMANOVA tests provided evidence that temperature was the key environmental factor responsible for microbial community dynamics, while pH, H2S, and SO2 influenced the abundance of specific microbial groups. When archaeal community composition was analyzed, the majority of detected OTUs correlated negatively with temperature, and few correlated positively with pH. Key Words: Microbial diversity—PhyloChip G3—Acidophilic—Thermophilic—Hot springs—Iceland. Astrobiology 14, 229–240.
Höfundur: admin
Little is understood regarding the phylogeny and metabolic capabilities of the earliest colonists of volcanic rocks, yet these data are essential for understanding how life becomes established in and interacts with the planetary crust, ultimately contributing to critical zone processes and soil formation. Here, we report the use of molecular and culture-dependent methods to determine the composition of pioneer microbial communities colonising the basaltic Fimmvörðuháls lava flow at Eyjafjallajökull, Iceland, formed in 2010. Our data show that 3 to 5 months post eruption, the lava was colonised by a low-diversity microbial community dominated by Betaproteobacteria, primarily taxa related to non-phototrophic diazotrophs such as Herbaspirillum spp. and chemolithotrophs such as Thiobacillus. Although successfully cultured following enrichment, phototrophs were not abundant members of the Fimmvörðuháls communities, as revealed by molecular analysis, and phototrophy is therefore not likely to be a dominant biogeochemical process in these early successional basalt communities. These results contrast with older Icelandic lava of comparable mineralogy, in which phototrophs comprised a significant fraction of microbial communities, and the non-phototrophic community fractions were dominated by Acidobacteria and Actinobacteria.
Lipid decomposition of saithe (Pollachius virens) light and dark muscles was monitored during frozen storage at −25 °C of raw (up to 18 months) and cooked products. Samples were cooked after 0, 6 and 12 months raw storage then refrozen and stored at −25 °C for 12 months to determine the stability of cooked-then-stored samples. Fatty acid profiles, formation of hydroperoxides (PV), thiobarbituric acid reactive substances (TBARS), fluorescence compounds (OFR) and free fatty acids (FFA) were evaluated throughout the storage for all samples. In general, results indicated that enzymatic lipolysis was the driving factor influencing the quality of saithe over raw storage and it mostly affected polyunsaturated lipids in the light muscle. Cooking, however, inhibited FFA formation and induced formation of PV and TBARS. This behavior was more evident in samples cooked after long raw storage periods. The initial quality of the raw material before cooking is therefore critical with regard to oxidative stability of cooked fish products.
Lipid deterioration of two lean fish species, saithe (Pollachius virens) and hoki (Macruronus novaezelandiae), during frozen storage at −20 and −30 °C (up to 18 months) was studied. Lipid composition, lipid oxidation and hydrolysis, and sensory attributes were evaluated on both light and dark muscles of the fish species. Results showed significant lipid deterioration with extended storage time, but lower storage temperature showed significantly more preservative effects. A marked difference was observed between the composition of dark muscle of hoki and saithe. Polyunsaturated fatty acids were the predominant lipids in dark muscle of saithe, while monounsaturated fatty acids were predominant in dark muscle of hoki. Further, the hydrolytic activity differed greatly between dark muscle of hoki and saithe, with significantly lower activity observed in hoki. Present results indicate that both tertiary lipid oxidation and hydrolysis products are appropriate for assessing lipid deterioration of saithe and hoki light muscle during frozen storage.
Near infrared spectroscopy (NIR) was applied to estimate lipid composition and degradation of two lean fish species, saithe (Pollachius virens) and hoki (Macruronus novaezelandiae). Calibration models were developed, using partial least squares (PLS) regression, for total lipid content and composition, free fatty acids (FFA), thiobarbituric acid reactive substances (TBARS) and fluorescent interaction compounds (OFR). Coefficients of determination for calibration (R2cv) and root-mean-square error of cross validation (RMSECV) ranged from 0.82 to 0.99 and 0.66 to 3.69 for hoki and from 0.64 to 0.99 and 0.06 to 2.65 for saithe, respectively. The validations of the calibrations indicated that lipid composition and FFA of hoki and saithe can be estimated by NIR with good accuracy. Furthermore, NIR differentiate fish muscles with low, medium and high concentration of OFR and TBARS. Overall, the results demonstrate the potential for use of NIR spectroscopy as an objective and non-destructive method to inspect the lipid characteristics and quality of frozen lean fish.
As the ice cap of the Arctic diminishes due to global warming, the polar sailing route will be open larger parts of the year. These changes are likely to increase the pollution load on the pristine Arctic due to large vessel traffic from specific contaminant groups, such as polycyclic aromatic hydrocarbons (PAHs). A well-documented baseline for PAH concentrations in the biota in the remote regions of the Nordic Seas and the sub-Arctic is currently limited, but will be vital in order to assess future changes in PAH contamination in the region. Blue mussels (Mytilus edulis) were collected from remote sites in Greenland, Iceland, the Faroe Islands, Norway and Sweden as well as from urban sites in the same countries for comparison. Cod (Gadus morhua) was caught north of Iceland and along the Norwegian coast. Sixteen priority PAH congeners and the inorganic trace elements arsenic, cadmium, mercury and lead were analysed in the blue mussel samples as well as PAH metabolites in cod bile. Σ16PAHs ranged from 28 ng/g dry weight (d.w.) (Álftafjörður, NW Iceland) to 480 ng/g d.w. (Ísafjörður, NW Iceland). Mussel samples from Mjóifjörður, East Iceland and Maarmorilik, West Greenland, contained elevated levels of Σ16PAHs, 370 and 280 ng/g d.w., respectively. Levels of inorganic trace elements varied with highest levels of arsenic in mussels from Ísafjörður, Iceland (79 ng/g d.w.), cadmium in mussels from Mjóifjörður, Iceland (4.3 ng/g d.w.), mercury in mussels from Sørenfjorden, Norway (0.23 ng/g d.w.) and lead in mussels from Maarmorilik, Greenland (21 ng/g d.w.). 1-OH-pyrene was only found above limits of quantification (0.5 ng/mL) in samples from the Norwegian coast, ranging between 44 and 140 ng/ml bile. Generally, PAH levels were low in mussels from the remote sites investigated in the study, which indicates limited current effect on the environment.
The co-authors of this paper hereby state their intention to work together to launch the Genomic Observatories Network (GOs Network) for which this document will serve as its Founding Charter. We define a Genomic Observatory as an ecosystem and/or site subject to long-term scientific research, including (but not limited to) the sustained study of genomic biodiversity from single-celled microbes to multicellular organisms.
An international group of 64 scientists first published the call for a global network of Genomic Observatories in January 2012. The vision for such a network was expanded in a subsequent paper and developed over a series of meetings in Bremen (Germany), Shenzhen (China), Moorea (French Polynesia), Oxford (UK), Pacific Grove (California, USA), Washington (DC, USA), and London (UK). While this community-building process continues, here we express our mutual intent to establish the GOs Network formally, and to describe our shared vision for its future. The views expressed here are ours alone as individual scientists, and do not necessarily represent those of the institutions with which we are affiliated.
The aim was to develop a Quality Index Method (QIM) scheme for fresh tilapia fillets and evaluate the scheme in a shelf life study. Farmed tilapia fillets were stored at 1 and −1°C for up to 20 days, and changes during storage were observed with sensory evaluation using the QIM scheme and General Descriptive Analysis (GDA), total viable counts (TVC), and hydrogen sulphide (H2S) producing bacteria. The maximum shelf life of fillets stored at1 and −1°C was determined with GDA and microbial counts as 16 and 19 days, respectively. A high correlation of R2 = 0.943 between Quality Index (QI) and storage time at 1C° was found to be 0.843 at −1°C. At the end of shelf life, the QI was 5.3 and 6.5 out of a maximum score of 15 for fillets stored at 1 and −1°C, respectively. Total viable counts and H2S-producing bacteria showed an increasing trend during storage time for both groups. At the end of shelf life, TVC was log 7 cfu/g in the flesh of both groups, with H2S producing bacteria constituting a higher proportion (log 6 cfu/g) of the total. The scheme was modified at the end of the study to better characterize deskinned farmed tilapia fillets.
Íslenskir ferskfiskútflytjendur notast gjarna við kælimottur til að viðhalda lágu hitastigi ferskfiskafurða í flutningi, einkum flugflutningi. Kælimotturnar innihalda venjulega annað hvort ís eða þá einhvers konar gel, sem nauðsynlega inniheldur þannig efni að það megi komast í snertingu við fiskinn ef mottan rofnar, þ.e. innihald mottunnar er „food-grade“.
Á erlendum mörkuðum er úrval umræddra kælimotta allvítt en hér á landi eru stærstu söluaðilar kælimotta fyrir ferskan fisk Promens Tempra í Hafnarfirði og Ísgel á Blönduósi. Tempra framleiðir ísmottur, sem einungis innihalda vatn og Ísgel framleiðir gelmottur og hefur því verið haldið fram að mikill munur geti verið á kæligetu umræddra kælimotta. Til að athuga það rannsökuðu verkfræðinemarnir Hilmar Arnarson og Sandra Björg Helgadóttir nýlega bæði bræðslumark og kæligetu ísmotta frá Tempru og gelmotta frá Ísgel í námskeiðinu Fiskiðnaðartækni 2 við Háskóla Íslands.
Í tilrauninni komu þau fyrir hitasíritum innan í kælimottum, sem pakkað var í frauðplastkassa. Kössunum var komið fyrir í frysti í nokkra daga áður en þeir stóðu við stofuhita uns kælimotturnar voru að fullu þiðnaðar. Hitamælingarnar leiddu ekki í ljós marktækan mun á hvorki bræðslumarki ís- og kælimottanna (hann var u.þ.b. 0,0 +/- 0,3 °C) né kæligetu (hæfileika kælimottanna til að viðhalda lágu hitastigi matvöru), sjá mynd 1.
Nánari upplýsingar veitir Sigurjón Arason, prófessor við Háskóla Íslands og yfirverkfræðingur Matís.
Mynd 1. Hitastig innan í ísmottum frá Promens Tempra og gelmottum frá Ísgel á meðan þíðingu stendur.
Tengiliður
Ólafur Reykdal
Verkefnastjóri
olafur.reykdal@matis.is
Kornafurðir og kornmarkaðir við norður Atlantshaf / Cereal Products And Markets In The Northern Periphery Region
Forverkefni um kornmarkaði og kornafurðir úr svæðisbundnu korni var unnið á tímabilinu september 2013 til mars 2014. Verkefnið var styrkt af Norður‐ slóðaáætluninni (Northern Periphery Promramme, NPP). Þátttakendur komu frá Íslandi, N‐Noregi, Færeyjum, Orkneyjum og Nýfundnalandi. Markmið verkefnis‐ ins var að: (1) Byggja upp samstarfsnet um kornrannsóknir. (2) Afla upplýsinga um kornframleiðslu og kornnýtingu á hverju svæði um sig og leita nýrra markaða og samstarfsaðila. (3) Leggja drög að umsókn um stórt kornverkefni. Þátttakendur greindu upplýsingar um kornframleiðslu og korninnflutning. Í ljós komu tækifæri til að láta innlenda framleiðslu koma í stað innflutnings. Kornmarkaðir og þróun markaða var tekin til skoðunar og mat var lagt á stærð markaða. Það ætti að vera mögulegt að auka innlenda framleiðslu á ýmsum kornvörum svo sem bökunarvörum, morgunkorni, pasta og áfengum drykkjum. Þátttökulöndin / svæðin eru á mismunadi stigi með tilliti til kornræktar og því þarf þróun kornvara að taka mið af aðstæðum.
A preparatory project scoping new markets and products from local cereals in several parts of the Northern Periphery Programme (NPP) area, was implemented between September 2013 and March 2014. The project included partners from the following regions: Iceland, N‐Norway, Faroe Islands, Orkney and Newfoundland. The project aim was to: (1) Build up a collaborative R&D network on cereals. (2) Review cereal production and utilization in each partner region and identify potential new markets and collaborators. (3) Develop a proposal for a main project. Partners quantified the domestic cereal production and import of cereals. Opportunities were found where imported cereals might be replaced by local products. Cereal markets and food trends were studied and the size of the market for cereal products was estimated. It is possible to increase the use of local cereals for production of many foods: bakery products, breakfast cerals, pastas and alcoholic beverages. The regions differ with regard to cereal production and development of cereal products should take the situation into account.