Minor Genera Research Articles

A new species of Pseudotsuga (Pinaceae) from the lower Miocene of Lesvos, Greece, and its palaeogeographical and palaeoclimatic implications

A new species of Pseudotsuga (Pinaceae) from the lower Miocene of Lesvos, Greece, and its palaeogeographical and palaeoclimatic implications

Redefining the megagenus Erica L. (Ericaceae): the contributions of E. G. H. Oliver and I. M. Oliver (née Nitzsche) to taxonomy and nomenclature.

The megagenus Erica L. (Ericaceae), as it is recognised today, includes 851 species of evergreen shrubs or small trees, the majority of which are endemic to the Cape Floristic Region of South Africa. From the first descriptions in Linnaeus's Genera plantarum, a succession of authors ascribed the steadily accumulating numbers of known species to various of a total of 72 different genera. Until the latter half of the twentieth century, so called 'minor genera' such as Philippia Klotzsch and Blaeria L. were still recognised for many African species. The now uncontroversial inclusive circumscription of Erica, and a substantial proportion of its currently recognised species diversity, was conceptualised, described, and illustrated by the South African botanists E. G. H. ('Ted') Oliver and Inge M. Oliver in a succession of works published from 1964 to the present day. We review the historical development of generic delimitation in Erica sens. lat., focusing on the contribution of the Olivers to the current state of systematic knowledge of the genus, and presenting an overview and complete lists of literature and of taxa that they authored.

Presepsin as a biomarker of bacterial translocation and an indicator for the prescription of probiotics in cirrhosis.

The gut-liver axis and bacterial translocation are important in cirrhosis, but there is no available universal biomarker of cellular bacterial translocation, for which presepsin may be a candidate. To evaluate the relationship of the blood presepsin levels with the state of the gut microbiota in cirrhosis in the absence of obvious infection. This study included 48 patients with Child-Pugh cirrhosis classes B and C and 15 healthy controls. The fecal microbiome was assessed using 16S rRNA gene sequencing. Plasma levels of presepsin were measured. A total of 22 patients received a probiotic (Saccharomyces boulardii) for 3 months. Presepsin levels were higher in patients with cirrhosis than in healthy individuals [342 (91-2875) vs 120 (102-141) pg/mL; P = 0.048]. Patients with elevated presepsin levels accounted for 56.3% of all included patients. They had lower levels of serum albumin and higher levels of serum total bilirubin and overall severity of cirrhosis as assessed using the Child-Pugh scale. Patients with elevated presepsin levels had an increased abundance of the main taxa responsible for bacterial translocation, namely Bacilli and Proteobacteria (including the main class Gammaproteobacteria and the minor taxa Xanthobacteraceae and Stenotrophomonas), and a low abundance of bacteria from the family Lachnospiraceae (including the minor genus Fusicatenibacter), which produce short-chain fatty acids that have a positive effect on intestinal barrier function. The presepsin level directly correlated with the relative abundance of Bacilli, Proteobacteria, and inversely correlated with the abundance of Lachnospiraceae and Propionibacteriaceae. After 3 months of taking the probiotic, the severity of cirrhosis on the Child-Pugh scale decreased significantly only in the group with elevated presepsin levels [from 9 (8-11) to 7 (6-9); P = 0.004], while there were no significant changes in the group with normal presepsin levels [from 8 (7-8) to 7 (6-8); P = 0.123]. A high level of presepsin before the prescription of the probiotic was an independent predictor of a greater decrease in Child-Pugh scores (P = 0.046), as well as a higher level of the Child-Pugh scale (P = 0.042), but not the C-reactive protein level (P = 0.679) according to multivariate linear regression analysis. The level of presepsin directly correlates with the abundance in the gut microbiota of the main taxa that are substrates of bacterial translocation in cirrhosis. This biomarker, in the absence of obvious infection, seems important for assessing the state of the gut-liver axis in cirrhosis and deciding on therapy targeted at the gut microbiota in this disease.

Effects of monensin and cashew nut-shell extract on bacterial community composition in a dual-flow continuous culture system.

The objective of this study was to evaluate the effects of including monensin and two doses of CNSE in a high producing dairy cow diet on ruminal bacterial communities. A dual-flow continuous culture system was used in a replicated 4 × 4 Latin Square design. A basal diet was formulated to meet the requirements of a cow producing 45kg of milk per d (17% crude protein and 27% starch). There were four experimental treatments: the basal diet without any feed additive (CON), 2.5 μM monensin (MON), 100ppm CNSE granule (CNSE100), and 200ppm CNSE granule (CNSE200). Samples were collected from the fluid and solid effluents at 3, 6, and 9h after feeding; a composite of all time points was made for each fermenter within their respective fractions. Bacterial community composition was analyzed by sequencing the V4 region of the 16S rRNA gene using the Illumina MiSeq platform. Treatment responses for bacterial community structure were analyzed with the PERMANOVA test run with the R Vegan package. Treatment responses for correlations were analyzed with the CORR procedure of SAS. Orthogonal contrasts were used to test the effects of (1) ADD (CON vs. MON, CNSE100, and CNSE200); (2) MCN (MON vs. CNSE100 and CNSE200); and (3) DOSE (CNSE100 vs. CNSE200). Significance was declared at P ≤ 0.05. We observed that the relative abundance of Sharpea (P < 0.01), Mailhella (P = 0.05), Ruminococcus (P = 0.03), Eubacterium (P = 0.01), and Coprococcus (P < 0.01) from the liquid fraction and the relative abundance of Ruminococcus (P = 0.03) and Catonella (P = 0.02) from the solid fraction decreased, while the relative abundance of Syntrophococcus (P = 0.02) increased in response to MON when compared to CNSE treatments. Our results demonstrate that CNSE and monensin have similar effects on the major ruminal bacterial genera, while some differences were observed in some minor genera. Overall, the tested additives would affect the ruminal fermentation in a similar pattern.

Hygienic Evaluation of Electrolyzed or Ozonated Water-Washed Apples Stored under Different Temperatures and Relative Humidity Conditions

The presence of spoilage and pathogenic microorganisms is a concern for the safety of apples. In the present study, we evaluated the hygienic status of electrolyzed water (EW)- or ozonated water (OW)-washed apples, which were stored over 2 weeks under the combination of 2 different temperatures (25 and 30°C) and 2 different relative humidity (RH) conditions (85 and 90%). The average numbers of bacteria or fungi from unwashed and washed apples (EW or OW) did not show statistically significant differences at storage for 0, 1, or 2 weeks and had an increased tendency as the storage temperature, RH, and period increased. Identification of fungal isolates from apples revealed 3 main genera (Fusarium sp., Trichoderma sp., and Alternaria sp.) together with 8 minor genera (Meyerozyma sp., Aspergillus sp., Glomerella sp., Neofusicoccum sp., Penicillium sp., Hypoxylon sp., Talaromyces sp., and Coprinellus sp.). Moreover, sensory tests using EW- or OW-washed apples showed that OW did not significantly affect 5 quality characteristics (appearance, taste, flavor, texture, and overall acceptability). Our data suggest that EW or OW washing did not significantly reduce the levels of microorganisms on apples relative to the unwashed and that EW or OW washing did not deteriorate the quality of washed apples.

Crossiellidines A-F, Unprecedented Pyrazine-Alkylguanidine Metabolites with Broad-Spectrum Antibacterial Activity from Crossiella sp.

Crosiellidines are intriguing pyrazine-alkylguanidine metabolites isolated from the minor actinomycete genus Crossiella. Their structures present an unprecedented 2-methoxy-3,5,6-trialkyl pyrazine scaffold and uncommon guanidine prenylations, including an exotic O-prenylated N-hydroxyguanidine moiety. The novel substitution pattern of the 2-methoxypyrazine core inaugurates a new class of naturally occurring pyrazine compounds, the biosynthetic implications of which are discussed herein. Isotopic feeding and genome analysis allowed us to propose a biosynthetic pathway from arginine. The crossiellidines exhibited remarkable, broad-spectrum antibacterial activity.

Uncovering the Microbiota of Bagworm Metisa plana (Lepidoptera: Psychidae) in Oil Palm Plantations in Malaysia.

Bagworm Metisa plana is one of the major pests in Malaysia's oil palm plantation, with infestation resulting in huge economical loss. Currently, the microbial profile of the bagworm has yet to be study. Understanding the biology of the pest such as the bacterial community is crucial as bacteria associated with insects often provide benefits to the insect, giving the insect host a better chance of survival. Here, 16S amplicon sequencing was used to identify the bacteria community of M. plana. Additionally, two comparisons were made, the bacterial communities between two larval stages (early instar stage and late instar stage) from outbreak area; the bacterial communities of late instar stage larvae from non-outbreak between outbreak areas. From this study, it was found that the bacterial community of M. plana consisted of Proteobacteria, Actinobacteria, Bacterioidetes, Firmicutes and other minor phyla, with Proteobacteria being the most dominant phylum. Furthermore, bacterial genera of M. plana consisted of Pantoea, Curtobacterium, Pseudomonas, Massilia and other minor genera, with Pantoea being the most dominant. It was also found that the alpha and beta diversity in both comparisons were not significantly different. We present our data as a first insight towards the bacterial community of M. plana, paving a way towards understanding the biology of the bagworm M. plana.

Species-specific secondary metabolism by actinomycetes of the genus Phytohabitans and discovery of new pyranonaphthoquinones and isatin derivatives.

To further exploit secondary metabolic potential of a minor actinomycete genus Phytohabitans within the family Micromonosporaceae, metabolite profiling by HPLC-UV analysis, combined with 16S rDNA sequence-based phylotyping were attempted on seven Phytohabitans strains available at the public culture collection. The strains were grouped into three clades and each exhibited unique and distinct metabolite profiles, which were highly conserved among strains within the same clade. These results were consistent with previous observations on two other actinomycetes genera, reconfirming species-specificity of secondary metabolite production, which were conventionally thought to be strain-specific. A strain RD003215, belonging to the P. suffuscus clade, produced multiple metabolites, some of which were presumed to be naphthoquinones. Liquid fermentation followed by chromatographic separation of the broth extract led to the discovery of three new pyranonaphthoquinones, designated habipyranoquinones A-C (1-3), and one new isatin derivative, (R)-N-methyl-3-hydroxy-5,6-dimethoxyoxindole (4), along with three known synthetic compounds, 6,8-dihydroxydehydro-α-lapachone (5), N-methyl-5,6-dimethoxyisatin (6), and 5,6-dimethoxyisatin (7). Structures of 1-4 were unequivocally elucidated by NMR, MS, and CD spectral analysis, with assistance of density functional theory-based NMR chemical shift prediction and ECD spectral calculation. Compound 2 displayed antibacterial activity against Kocuria rhizophila and Staphylococcus aureus with MIC 50 µg/mL and cytotoxicity against P388 murine leukemia cells with an IC50 value of 34 µM. Compounds 1 and 4 also showed cytotoxicity against P388 cells with IC50 values of 29 and 14 µM, respectively.

Таксономический анализ макрофитобентоса акватории памятника природы «Прибрежный аквальный комплекс у мыса Фиолент» (Черное море)

An increase in anthropogenic impact on protected marine objects makes their biodiversity decrease. There is a need to make forecasts of the impact on their coastal zone. The forecasts should be based on the results of long-term observations, which were carried out sporadically in the water area of the natural monument "Coastal aquatic complex near Cape Fiolent" in the middle of the 20th century. Information about the flora of the monument is scarce and needs to be updated. The aim of the study was to investigate the species composition, taxonomic structure and variability of the monument macrophytobenthos in modern conditions. Algological works were carried out by the method of vertical hydro-botanical sections in July 2021. Samples were taken by a diver at depths of 0.5; 1, 3, 5, 10 and 15 m in the eastern and western sections. A list of 90 species, 63 genera, 35 families, 24 orders, 5 classes Chlorophyta, Ochrophyta, Rhodophyta was compiled based on data for the period 1977 - 2021. 13 species have a conservation status. The basis of phytocenosis is formed by minor genera and the floristic spectra - by a limited number of superspecific taxa. In 2021 the phytocenosis of the monument included 52 species. The flora of the monument is warm-water, subtropical, and its habitat is mesotrophic. Comparison of the composition of phytocenoses in the eastern and western sites revealed no fundamental differences. Low values of Jaccard's coefficient indicate bathymetric isolation of the floristic composition. A direct dependence of the number of species on depth was revealed. It is shown that qualitative heterogeneity of phytocenoses in different decades is not as pronounced as within the same decade.

Gut microbiome-modulating properties of a polyphenol-enriched dietary supplement comprised of hibiscus and lemon verbena extracts. Monitoring of phenolic metabolites

• Metabolaid® is a dietary supplement comprising hibiscus and lemon verbena extracts. • Metabolaid®, in a dose-dependent manner, modulated the gut bacteriome. • Phenolic compounds in Metabolaid® were rapidly metabolized by the gut microbiota. • Metabolaid® promoted increases in SCFAs production, particularly butyric acid. This paper investigates the impact of a polyphenol-enriched supplement comprised of hibiscus ( Hibiscus sabdariffa ) and lemon verbena ( Lippia Citriodora ) (brand name Metabolaid®) on gut microbiota composition and functionality, by performing fermentations with human faecal microbiota under gut-simulated conditions. Results indicated that Metabolaid®, in a dose-dependent manner, modulated the gut bacteriome to higher relative abundances of some major genera (>3% of relative abundance) such as Bifidobacterium , Blautia and Faecalibacterium and of other minor genera such as Prevotella and Akkermansia . Metabolaid® also promoted increases in short-chain fatty acids (SCFAs) production, particularly butyric acid. On the other hand, it was confirmed that the compounds present in the Metabolaid® supplement (anthocyanins, verbascoside and hibiscus acid) were rapidly metabolized by the gut microbiota. Overall, these results reveal a certain level of gut microbiota-modulating properties of Metabolaid® that could be implicated, at least partially, in the mechanisms behind the potential beneficial effects of this supplement in obesity.

Portuguese cacholeira blood sausage: A first taste of its microbiota and volatile organic compounds

Among typical Portuguese sausages, the cacholeira blood sausage undoubtedly represents one of the most popular preparations. To the authors' knowledge, a lack of information on both the microbiota and the volatile organic compounds (VOCs) of this blood-containing sausage emerges from the available scientific literature. This study represents the first characterization of physico-chemical, microbiological and volatile traits of Portuguese cacholeira blood sausage. To this end, ready-to-eat cacholeira blood sausages were collected from two production batches manufactured in summer (batch 1) and autumn (batch 2). Viable counts showed active microbial communities mainly composed by lactic acid bacteria, coagulase negative cocci, enterococci and eumycetes. The metataxonomic approach showed a simple bacterial composition, which was dominated by Lactobacillus sakei in both the analyzed batches (1 and 2) considered. Carnobacterium, Enterococcus, Kluyvera, Lactococcus and Serratia were found as minor genera. The mycobiota varied according to the production season. Batch 1 was dominated by Starmerella apicola, Debaryomyces hansenii and Candida tropicalis, whereas batch 2 was dominated by D. hansenii. Moreover, Aspergillus spp., Kurtzmaniella zeylanoides, Saccharomyces cerevisiae, Kurtzmaniella santamariae, Brettanomyces bruxellensis and Pichia kluyveri were detected in both the batches as minority species. Seventy-two volatile compounds were identified, including esters, phenols, terpenoids, acids, alcohols, ketones, aldehydes, lactones, furans, sulphur and nitrogen compounds. Significant differences were seen in the amount of some compounds, as a feasible consequence of differences in the raw materials, artisan production and seasonality.

Screening of Burkholderia spp. from oil palm plantation with antagonistic properties against Ganoderma boninense

Abstract. Yurnaliza. Rambe DI, Sarimunggu L, Purba M, Nurwahyuni I, Lenny S, Lutfia A, Hartanto A. 2020. Screening of Burkholderia spp. from oil palm plantation with antagonistic properties against Ganoderma boninense. Biodiversitas 21: 3431-3437. Burkholderia spp. are ubiquitous diazotrophic bacteria within β-Proteobacteria group, known for its occurrence in variety of niches from aquatic to terrestrial habitats and as endophytes. Beneficial strains of Burkholderia have been reported as plant growth-promoting rhizobacteria or as antagonistic bacteria against phytopathogenic fungi. This study evaluated the potential of multiple strains of Burkholderia spp. recovered from three ecological niches, such as rhizosphere, humus soil, and root endophytes of oil palm plantations in North Sumatra to suppress the growth of basal stem rot causative agent in oil palm (Elaeis guineensis Jacq.) by Ganoderma boninense Pat. The antagonistic isolates were identified on the basis of molecular identification using 16S rDNA sequence (27F–1462R), revealing twelve isolates (48%) as members of Burkholderia cepacia complex (Bcc), with other minor genera, such as Chitinophaga, Klebsiella, Mycobacterium, Paenibacillus, Rhizobium, Serratia, Stenotrophomonas, and Xanthomonas. The antagonistic activities as expressed in the percentage inhibition of radial growth (PIRG) against G. boninense were considerably potential with the highest percentage of 55%. In comparison, the crude extract (MeOH, EtOAc) was also tested against G. boninense colonies showing PIRG from 0 to 38%. Majority of isolates did not show any visible chitinolytic activity based on plate assay, in exception to B. contaminans RC02 while most of them were producers of glucanase. The collection of indigenous Burkholderia spp. originating from North Sumatran oil palm plantations, i.e. B. cepacia, B. contaminans, B. metallica, and B. stagnalis may then be considered as potential biocontrol agents against G. boninense based on their antagonistic activities, antifungal properties, and hydrolytic enzyme activities.

Metagenomics analysis of rhizospheric bacterial communities of Saccharum arundinaceum growing on organometallic sludge of sugarcane molasses-based distillery.

The present paper aims to explore the rhizospheric bacterial communities associated with Saccharum arundinaceum grown on organometallic pollutants-rich hazardous distillery sludge. The sequence analysis of 16S rRNA V3-V4 hypervariable region with Illumina MiSeq platform showed 621,897 OTUs derived from rhizospheric and non-rhizospheric distillery sludge samples out of 1,191,014 and 901,757 sequences read, respectively. The major phyla detected in rhizospheric sludge sample were Proteobacteria (50%), Bacteriodetes (33%), Firmicutes (5%) Gemmatimonadetes (2%), Chloroflexi (2%), and Tenericutes (2%). The dominant three genera were detected as Rheinheimera (21%), Sphingobacterium (17%), and Idiomarina (8%). In addition, other minor genera such as uncultured Bacillus (4%), Acidothermus (4%), Bacillus (3%), Pseudomonas (2%), Flavobacterium (2%), uncultured bacterium (2%), Parapedobacter (2%), Alcanivorax (2%), Acholeplasma (2%), Hyphomonas (1%), and Aquamicrobium were also detected (1%) in rhizospheric sludge. Our results suggested that rhizospheric bacterial communities associated with S. arundinaceum were substantially different in richness, diversity, and relative abundance of taxa compared to non-rhizospheric sludge. Further, the comparative organic pollutant analysis from non-rhizospheric and rhizospheric sludge samples through GC-MS analysis revealed the disappearance of few compounds and generation of some compounds as new metabolic products by the activity of rhizospheric bacterial communities. The results of this study will be helpful in understanding the role of rhizospheric bacterial communities responsible for degradation and detoxification of complex organometallic waste and, thus, can help in designing appropriate phytoremediation studies for eco-restoration of polluted sites.

Removal of malodorant skatole by two enriched microbial consortia: Performance, dynamic, function prediction and bacteria isolation

Malodor emission has become one of the major challenges in animal husbandry. Skatole, one of the most offensive odorous compounds, can cause several diseases to organisms and is resistant to biodegradation. However, the microbial community information for skatole degradation has yet to be reported. In this study, the aerobic sequencing batch reactors with two different inocula were constructed. Both Group N (sample from cattle house) and Group E (sample from goose house) could efficiently degrade skatole after 70days operation under conditions of pH7.0-9.0 and temperature 20-40°C. High-throughput sequencing results showed that the α-diversity in Group N was higher than that in Group E, while neither of them changed during the whole operation process. Bacterial community structures in both groups shifted. Generally, Lactococcus, Pseudomonas and Flavobacterium remarkably reduced, while Arthrobacter became the dominant population. Function prediction results indicated that the xenobiotics biodegradation and metabolism category was significantly up-regulated in Group E but remained unchanged in Group N. On the other hand, culture-dependent technique was applied and ten bacteria were obtained from the sludges. Two strains belonged to Rhodococcus, a minor genus in the communities, were firstly proven to harbor excellent skatole-degrading capacity. This study proved that skatole could be effectively removed by activated sludges, and the non-core bacteria Rhodococcus would be functionally important in the degradation process. These findings provide new insights into our understanding of skatole biotransformation process, and offer valuable bacterial resources for bioremediation application.

Human Milk Microbiome and Maternal Postnatal Psychosocial Distress.

Human milk contains many bioactive components, including bacteria, which are transferred to the developing infant through breastfeeding. Milk bacteria appear to, amongst others, originate from the maternal gut. A mother’s postnatal psychosocial distress may alter maternal gut microbiota, which in turn may affect the bacteria present in milk. The aim of this study was to explore whether maternal postnatal psychosocial distress was related to alterations in the relative abundances of specific bacteria and to milk microbial diversity. Healthy mothers (N = 77; N = 51 with complete data) collected breast milk samples at 2, 6, and 12 weeks postpartum and filled in mood questionnaires on experienced stress, anxiety, and depressive symptoms at 6 weeks postpartum. A metataxonomic approach (16S rRNA gene sequencing (region V3 and V4) using Illumina MiSeq technology) was used to assess bacterial abundances and diversity. For the group as a whole, an increase in diversity of the milk bacterial community was observed during the first 3 months of breastfeeding (Shannon index). This general increase in diversity appears to be explained by an increase of Lactobacillus and other minor genera, together with a decrease in Staphylococcus. With respect to psychological distress and milk microbial composition, no significant differences in the relative abundance of major bacterial genera were detected between women with high (N = 13) and low (N = 13) psychosocial distress. However, progressive and distinct changes in the content of Firmicutes, Proteobacteria, and Bacteroidetes at the phylum level and Acinetobacter, Flavobacterium, and Lactobacillus at the genera level were observed in milk samples of women with low psychosocial distress. With respect to milk microbial diversity, high maternal psychosocial distress, compared to low maternal psychosocial distress, was related to significantly lower bacterial diversity in milk at 3 months post-delivery. Anxiety, stress, and depressive symptoms separately were unrelated to specific bacterial profiles. The current study suggests a potential relation between maternal psychosocial distress and milk microbiota, providing first evidence of a possible mechanism through which post-partum psychological symptoms may affect infant development and health.

Changes in rhizosphere bacterial communities associated with tree decline: grapevine esca syndrome case study.

An investigation was carried out on rhizosphere bacteria to determine if they may be associated with perennial crops affected by nonspecific decline, a phenomenon that is difficult to diagnose and prevent. Esca disease of grapevine was chosen for this case study because of its easy foliar symptom identification. Ribosomal DNA fingerprint analysis by polymerase chain reaction - denaturing gradient gel electrophoresis (PCR-DGGE), quantitative PCR (qPCR), and rDNA amplicon sequencing by next-generation sequencing (NGS) were adopted to investigate the bacterial communities associated with grapevines, which were selected for the presence and absence of external foliar symptoms in 11 vineyards. According to PCR-DGGE and qPCR, bacterial communities differed in site of origin (vineyards), but not between symptomatic and asymptomatic plants, whereas qPCR gave a significantly higher presence of total bacteria and Pseudomonas spp. in asymptomatic plants. NGS confirmed no difference between symptomatic and asymptomatic plants, apart from a few minor genera (<0.5%) such as Salinibacterium, Flavobacterium, Nocardia, and Janthinobacterium, which were, in all cases, higher in asymptomatic plants and whose functional role should be the object of further investigation. The fact that total bacteria and Pseudomonas were more abundant in the rhizosphere of asymptomatic grapevines and that some bacterial genera were associated with the latter, represents a new element when investigating the multiple-origin phenomenon such as esca disease of grapevine.

Characterization of Bacterial Microbiota in Tilapia Fillets Under Different Storage Temperatures.

This paper investigates the bacterial microbiota in tilapia fillets under cold (4°C), iced (0°C), and superchilled (-3°C) storage conditions. At 4°C, at least seven species/strains of Pseudomonas were detected in the fillets, five of which were dominant either at a certain stage or throughout the entire storage period. Shewanella was less dominant than Pseudomonas at 4°C, while Serratia became dominant after 6 days storage at 4°C. The microbiota in fillets stored at 0 and -3°C were very similar and rarely changed during storage, yet differed greatly from the microbiota at 4°C. Only two Pseudomonas species/strains grew at 0 and -3°C, one of which was the most dominant. A Vibrionimonas sp. not found at 4°C was found to be the second most dominant species at 0 and -3°C. Shewanella and Psychrobacter were also present at 0 and -3°C but were the minor genera. The most dominant strains at -3, 0, and 4°C were separately isolated and subjected to full length 16S rDNA sequencing, which demonstrated that they were identical and were Pseudomonas fluorescens. The changes of the total bacterial count and TVBN value of the fillets inoculated with the isolated P. fluorescens were very similar to those of fillets with natural microbiota. This implies that P. fluorescens is the most important spoiler of tilapia fillets at -3, 0, or 4°C. PRACTICAL APPLICATION: This research shows that fewer species of bacteria survive at 0 and -3°C than those at 4°C, while among these bacteria, the most important spoiler is P. fluorescens. This may provide some clues to extend the shelf life of tilapia fillets by taking some inhibitory measures targeted at P. fluorescens in the future.

Co-metabolic degradation of the antibiotic ciprofloxacin by the enriched bacterial consortium XG and its bacterial community composition

Ciprofloxacin is a broad spectral and highly refractory antibiotic. It is an emerging pollutant. This study aimed to utilise co-metabolism as a means to degrade ciprofloxacin by a bacterial consortium. The stable bacterial consortium XG capable of efficiently degrading ciprofloxacin was successfully established through successive acclimation of indigenous microorganisms. The consortium XG was primarily consisted of Achromobacter, Bacillus, Lactococcus, Ochrobactrum, and Enterococcus as well as at least other five minor genera. A novel strain YJ17 with CIP-degrading ability was isolated from the consortium and identified as Ochrobactrum sp. The consortium XG utilised amino acids, carbohydrates, and carboxylic acids at a rate approximately 16.6-243-fold greater than the other carbon substrates, but only slow utilisation of ciprofloxacin as a sole carbon source. Ciprofloxacin can be co-metabolized along with many carbon sources, attaining degradation rates up to 63%. Glycyl-l-glutamic acid, d-cellobiose, and itaconic acid are among the substrates most favourable for co-metabolism. The metabolites of ciprofloxacin were identified by LC-QTOF-MS. Co-metabolic degradation of ciprofloxacin by consortium XG led to the removal of essential functional groups from parent compound, thus resulting in formation of metabolites with less bioactive potency. Finally, a possible biochemical pathway for the degradation of ciprofloxacin was proposed. Consortium XG possesses high potential for bioremediation of ciprofloxacin-contaminated environments in the presence of a co-substrate.

Succession of bacterial microbiota in tilapia fillets at 4°C and in situ investigation of spoilers.

The succession of bacterial microbiota in tilapia fillets during cold storage at 4°C was investigated employing PCR-DGGE method. Results showed that Pseudomonas was the most dominant genus during entire storage period. Shewanella and Psychrobacter were also always present, but became dominant only after 3days of storage. Acinetobacter, Brevibacterium, Flavobacterium, Dietzia and Janthinobacterium were always the minor genera, among which Acinetobacter and Brevibacterium disappeared 6 days later, and Dietzia and Janthinobacterium only appeared at the end of storage. Further, the potential spoiler(s) of tilapia fillets at 4°C were investigated in situ. The spoilage ability of a specific group of bacteria was evaluated as follows: Certain preservatives were selectively added to fillets to inhibit a specific group of bacteria, and then the changes in spoilage degree of fillets were determined. In this way the spoilage ability of the inhibited bacteria was evaluated. Our experiments showed that protamine strongly inhibited Pseudomonas but rarely inhibited Psychrobacter, Acinetobacter and Brevibacterium, but garlic juice, on the contrary, strongly inhibited the latter three but rarely inhibited the former. The mixed preservative, which consisted of protamine and garlic juice, didn't play better than protamine alone in preventing the spoilage of fillets. This indicated that Psychrobacter, Acinetobacter and Brevibacterium contribute little to the spoilage of tilapia fillets.

The phylogenetic position of Choerodonicola Cribb, 2005 (Digenea: Opecoelidae) with a partial life-cycle for a new species from the blue-barred parrotfish Scarus ghobban Forsskål (Scaridae) in Moreton Bay, Australia

Choerodonicola Cribb, 2005 is a minor genus of opecoelid trematodes defined for species with exceptionally small eggs but otherwise generalised morphology. Four species are currently recognised, all from fishes collected in Japanese waters but each from different perciform families: a labrid, a scarid, a sparid and pinguipeds. We report on a new species, Choerodonicola arothokoros n. sp., from the blue-barred parrotfish Scarus ghobban Forsskål (Scaridae) collected in subtropical waters of Moreton Bay, south-east Queensland, Australia. Using genetic sequence data for the ITS2 rDNA marker, we matched adult C. arothokoros to intramollsucan stages discovered in an intertidal gastropod Herpetopoma atratum (Gmelin) (Vetigastropoda: Chilodontidae) collected in close proximity to the fish hosts. Notably, the cercariae lack a penetration stylet and are among the smallest known in the Opecoelidae. We provide the first assessment of the phylogenetic position of Choerodonicola based on sequence data generated for the phylogenetically informative 18S and 28S rRNA coding regions, for C. arothokoros and also C. renko Machida, 2014, which we recollected from the yellowback seabream Dentex hypselosomus Bleeker from the fish market in Minabe, Wakayama Prefecture, Japan. In our analyses, species of Choerodonicola resolved to neither of the major marine Plagioporinae (sensu lato) clades, clustering instead with Trilobovarium parvvatis Martin, Cutmore & Cribb, 2017, Podocotyloides parupenei (Manter, 1963) Pritchard, 1966 and Macvicaria magellanica Laskowski, Jeżewski & Zdzitowiecki, 2013. This clade is phylogenetically distinctive such that it has the potential to be recognised as a new opecoelid subfamily, but further investigation is required to establish the bounds for such a grouping and to determine the morphological and/or life-history patterns reflected by the phylogeny. Finally, we propose C. interruptus (Manter 1954) n. comb. for a species previously recognised in Plagioporus Stafford, 1904 and known only from Pseudolabrus miles (Schneider & Forster), a labrid endemic to New Zealand.