Submerged Fermentation of Animal Fat By-Products by Oleaginous Filamentous Fungi for the Production of Unsaturated Single Cell Oil

Animal waste fats were explored as a fermentation substrate for the production of high-value unsaturated single cell oil (SCO) using oleaginous fungi, Mucor circinelloides and Mortierella alpina. Both strains showed good growth and lipid accumulation when using animal fat as a single carbon source. The biomass concentration of 16.7 ± 2.2 gDCW/L and lipid content of 54.1%wt (of dry cell weight) were obtained for Mucor circinelloides in shake flask experiments, surpassing the biomass yield achieved in batch and fed-batch fermentation. In contrast, Mortierella alpina gave the highest biomass concentration (8.3 ± 0.3 gDCW/L) and lipid content (55.8%wt) in fed-batch fermentation. Fat grown Mortierella alpina was able to produce arachidonic acid (ARA), and the highest ARA content of 23.8%wt (of total lipid weight) was in fed-batch fermentation. Gamma-linolenic acid (GLA) was produced by both fungal strains. At the end of fed-batch fermentation, the GLA yields obtained for Mucor circinelloides and Mortierella alpina were 4.51%wt and 2.77%wt (of total lipid weight), respectively. This study demonstrates the production of unsaturated SCO-rich fungal biomass from animal fat by fermentation.

Assessing the exposure of Sidi M’Hamed Benali lake (Algeria) to Organo-chlorinated compounds and pesticides in fish

Sidi M’Hamed Benali lake (Algeria) is a reservoir used for recreational and fishing purposes that also harbors a rich fauna an flora. These are affected by use of pesticides in view of the increasing anthropogenic activities. In this study, levels of contaminants, polychlorinated biphenyls (PCBs), polybromo-diphényléthers (PBDEs), dichlorodiphenyltrichloroethanes (DDTs), and Lin-dane were measured using gas chromatography with electron capture detec-tion and gas chromatography mass spectrometry in four fish species (Cyprinus carpio, Barbus barbus, Hypophthalmichthys molitrix, Rutilus rutilus) of Sidi M'Hamed Benali lake. The results showed that PCBs, PBDEs and the insecticide Lindane contaminated the studied species but at concentrations, much lower that the guiding values. On the contrary, high levels of pp’DDE (p,p’dichlorodiphényldichloroéthylène) was recorded in all samples with values higher than the Maximum residue limit of 300 ng/g lipid weight (LW.) set by FAO with values as high as 3.87 x 103 ng/g LW (total DDTs) which indi-cated potential hazard not only to human consumers of the lake fishs but also a potential hazard expected to animals that prey on these fishes. 14 ng/g fresh weight (FW.) Canadian limit is also significantly lower than the values of fish from the studied lake (42-46 ng/g FW.). In light of these results, we conclude that this lake is exposed to organic pollution of anthropogenic origin and we encourage caution regarding the consumption of fish in this reservoir. It is time to make serious efforts to mitigate the lake pollution in order to protect aquatic wildlife for sustainable development.

Galleria mellonella larvae exhibit a weight-dependent lethal median dose when infected with methicillin-resistant Staphylococcus aureus

ABSTRACT Galleria mellonella is a recognised model to study antimicrobial efficacy; however, standardisation across the scientific field and investigations of methodological components are needed. Here, we investigate the impact of weight on mortality following infection with Methicillin-resistant Staphylococcus aureus (MRSA). Larvae were separated into six weight groups (180–300 mg at 20 mg intervals) and infected with a range of doses of MRSA to determine the 50% lethal dose (LD50), and the ‘lipid weight’ of larvae post-infection was quantified. A model of LD50 values correlated with weight was developed. The LD50 values, as estimated by our model, were further tested in vivo to prove our model. We establish a weight-dependent LD50 in larvae against MRSA and demonstrate that G. mellonella is a stable model within 180–260 mg. We present multiple linear models correlating weight with: LD50, lipid weight, and larval length. We demonstrate that the lipid weight is reduced as a result of MRSA infection, identifying a potentially new measure in which to understand the immune response. Finally, we demonstrate that larval length can be a reasonable proxy for weight. Refining the methodologies in which to handle and design experiments involving G. mellonella, we can improve the reliability of this powerful model.

Vaquitas (Phocoena sinus) continue to die from bycatch not pollutants

BackgroundThe vaquita of Mexico is critically endangered, with a population less than 19 individuals in 2018. The population continues to decline and gillnet use continues in vaquita habitat.MethodsNine vaquita carcases were examined from 2016 to 2018 to establish cause of death. Concentrations of polychlorinated biphenyls (PCBs), DDTs and polybrominated diphenyl ethers (PBDEs) in blubber (n=3) were determined using gas chromatography/mass spectrometry and faeces tested for domoic acid and saxitoxin.ResultsCarcases were in good nutritional status and had lesions and full stomachs consistent with fisheries bycatch. PCB, DDT and PBDE concentrations ranged between 94 and 180 ng/g, 500 and 1200 ng/g and 97 and 210 ng/g lipid weight, respectively, which are low compared with other marine mammals. No saxitoxin or domoic acid was detected.ConclusionThese findings support the conclusion that bycatch is the primary source of vaquita population decline and emphasise the need for stronger measures to eliminate gillnets from the Upper Gulf of California, Mexico.

Food source as a factor determining birds' exposure to hazardous organic pollutants and egg contamination

Alimentary exposure is the main factor determining halogenated organic compound pollution of wildlife, with birds’ eggs recognised as bioindicators of these contaminants and often used as a non-invasive monitoring tool. Comparisons of bird species from two aquatic environments, namely a marine coastal area (Gdansk Bay) and an inland reservoir (Włocławek Dam on the Vistula River), indicated significant differences in egg contamination. Herring gull eggs from Włocławek Dam had high concentrations of highly chlorinated dioxin (i.e. octachlorodibenzodioxin, which accounted for 37% of all polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo furans, PCDD/Fs). In contrast, eggs from terns feeding along the coastal area of the Southern Baltic contained high concentrations of lowly chlorinated furans (i.e. pentachlorodibezofuran, which accounted for 46 and 45% of all PCDD/Fs in eggs from the sandwich tern and common tern respectively). The congener patterns in terns’ eggs were similar to those reported previously for Baltic fish. Polychlorinated biphenyl congener 180 had the highest concentrations among the mono-ortho chlorinated biphenyls, whereas concentrations of non-dioxin-like chlorinated biphenyls were 10-fold higher than those of the other congeners analysed, but the congener pattern in eggs from both species (sandwich and common tern) was similar to that reported in other studies. Among the hexabromocyclododecane (HBCD) isomers, α-HBCD dominated in all eggs analysed (accounting for >97% of all HBCDs). The total HBCD concentration in gulls’ eggs from the inland reservoir was approximately half that in eggs from the common and sandwich terns (mean±s.d. 47.33±33.22v. 97.98±59.69 and 104.00±63.66ngg–1 lipid weight respectively).

High pollutant exposure level of the largest European community of bottlenose dolphins in the English Channel

The objective of this study was to assess the levels of persistent organic pollutants (POPs) and mercury (T-Hg) in the blubber and skin, respectively, of the free-ranging bottlenose dolphins, Tursiops truncatus, from the Normanno-Breton Gulf, one of the largest identified coastal population in Europe. Among all the POPs analysed in this study, the ∑NDL-PCBs were the most abundant compounds found in the blubber (mean: 1.33 × 105–0.65 × 105 ng.g−1 lipid weight (lw) for males and females respectively), followed by ∑DDX (1.11 × 104–4.67 × 103 ng.g−1 lw) > ∑DL-PCBs (8.06 × 103–2.62 × 103ng.g−1 lw) > ∑PBDEs (1.95 × 103–0.64 × 103ng.g−1 lw) > dieldrin (1.86 × 103–0.18 × 103 ng.g−1 lw) > ∑endosulfan (405–62 ng.g−1 lw) > HCB (86–52 ng.g−1 lw) > ∑HCHs (47–60 ng.g−1 lw) > ∑chlordane (24–0.97 ng.g−1 lw) > ∑PCDFs (0.3–0.1 ng.g−1 lw) > ∑PCDDs (0.06–0.05 ng.g−1 lw). The T-Hg concentrations were highly variable between individuals (2.45 × 103 ng.g−1 to 21.3 × 103 ng.g−1 dry weight, dw). The reported concentrations are among the highest reported for cetaceans. We strongly recommend that the Normanno-Breton Gulf be a special area of conservation (cSAC) candidate because it contains the last large European population of bottlenose dolphins (rare or threatened within a European context) designated under the EC Habitats Directive.

Determination of plasma concentrations of organochlorine pesticides and polychlorinated biphenyls in pet cats and dogs

The aim of this study was the determination of plasma concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in cats and dogs and evaluation of their prevalence and possible effects. The concentrations of nine OCPs, such as α-hexachlorocyclohexane (HCH), β-HCH, γ-HCH, hexachlorobenzene (HCB), aldrin, 2,4′-dichlorodiphenyltrichloroethane (2,4′-DDT), 4,4′-DDT, 2,4′-dichlorodiphenyldichloroethylene (2,4′-DDE) and 4,4′-DDE and 16 PCBs (PCB-28, -52, -70, -74, -81, -99, -101, -118, -138, -153, -156, -170, -180, -183, -187 and -208) were evaluated in the plasma samples of pet cats ( n = 15) and dogs ( n = 21). The concentrations of OCPs ranged from 1.12 ng g−1 lipid weight (lw) to 7.65 ng g−1 lw in cats and from 1.25 ng g−1 lw to 6.79 ng g−1 lw in dogs. In addition, mean PCB levels were 0.58–5.66 and 0.52–6.62 ng g−1 lw in cats and dogs, respectively. β-HCH, γ-HCH and PCB-138 levels were significantly higher in dogs ( p < 0.05). As far as could be determined, OCPs and PCBs were detected in the plasma samples of domestic cats and dogs in Turkey for the first time. Their concentrations were similar to those reported in earlier studies abroad. However, in contrast to other research, the levels of some OCPs were higher in dogs than in cats. It is concluded that, because of their high prevalence and potential health effects in animals and humans, OCP and PCB levels should be monitored systematically in domestic cats and dogs.

POLYCHLORINATED BIPHENYLS IN EDIBLE FISH FROM BLACK SEA, BULGARIA

Polychlorinated biphenyls (PCBs) can still be a problem for the aquatic environment. Fish species are a suitable indicator for the environmental pollution monitoring because they concentrate pollutants in their tissues directly from water. Concentrations of PCBs were measured in marine fish, collected from Bulgarian Black Sea coast in order to monitor the dynamics of these pollutants in 2007, 2010 and 2015. The fish species: goby (Neogobius melanostomus), sprat (Sprattus sprattus sulinus), horse mackerel (Trachurus Mediterraneus ponticus) and grey mullet (Mugil cephalus) were chosen because of their characteristic feeding behavior. The PCBs were determined by gas chromatography system with mass spectrometry detection. The Total PCBs ranged from 93.8 to 513.3 ng/g lipid weight (in grey mullet and goby, respectively). Levels of PCBs in goby and grey mullet decreased in 2010 and 2015. In order to assess the safety of fish as food were calculated TEQ. They are determined by the results of dioxin - like (dl) PCBs. TEQs were calculated from 0.01 to 0.04 pg TEQ/g ww and did not exceed the EC limit of 3 pg TEQ/g ww. The levels of PCBs in fish from Bulgarian Black Sea were comparable to those found in neighboring seas.

POLYCHLORINATED BIPHENYLS IN EDIBLE FISH FROM BLACK SEA, BULGARIA

Polychlorinated biphenyls (PCBs) can still be a problem for the aquatic environment. Fish species are a suitable indicator for the environmental pollution monitoring because they concentrate pollutants in their tissues directly from water. Concentrations of PCBs were measured in marine fish, collected from Bulgarian Black Sea coast in order to monitor the dynamics of these pollutants in 2007, 2010 and 2015. The fish species: goby (Neogobius melanostomus), sprat (Sprattus sprattus sulinus), horse mackerel (Trachurus Mediterraneus ponticus) and grey mullet (Mugil cephalus) were chosen because of their characteristic feeding behavior. The PCBs were determined by gas chromatography system with mass spectrometry detection. The Total PCBs ranged from 93.8 to 513.3 ng/g lipid weight (in grey mullet and goby, respectively). Levels of PCBs in goby and grey mullet decreased in 2010 and 2015. In order to assess the safety of fish as food were calculated TEQ. They are determined by the results of dioxin - like (dl) PCBs. TEQs were calculated from 0.01 to 0.04 pg TEQ/g ww and did not exceed the EC limit of 3 pg TEQ/g ww. The levels of PCBs in fish from Bulgarian Black Sea were comparable to those found in neighboring seas.

Organochlorine pesticide and polychlorinated biphenyl levels of horse mackerel (Trachurus sp.) caught from Marmara Sea coastal sites

The levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were assessed in horse mackerel (Trachurus sp.) samples collected monthly between October 2010 and October 2011 from four regions (Bosphorus, Bandırma, Gelibolu, Tekirdağ) in the Marmara Sea. α-Endosulfan and heptachlor were not detected in any fish samples. The annual average OCP levels among the regions ranged between 0.09–12.2 ng g−1 (wet weight), 0.8–168 (lipid weight), while the annual average PCB levels among the regions ranged between 0.55–4.98 ng g−1 (wet weight), and 7.01–116 (lipid weight), respectively. Total-DDT, total-HCH, PCB 138 and PCB 153 were the most predominant contaminants in the fish samples. There was no relation between lipid content of horse mackerel samples and residues of the contaminants. OCP and PCB levels detected in all of the fish samples were below the limits recommended by the EU Commission (2011), Food and Agricultural Organization of the United Nations (1983), U.S. Food and Drug Administration (2011) and Turkish Food Codex (2011).