Genome Insight and Description of Carotenoids-producing Croceicoccus Gelatinilyticus Sp. Nov., Isolated From the Tidal Flat Sediment

A novel Gram-staining-negative and short-rod-shaped bacterial strain designated as 1NDH52 T was isolated from tidal at sediments and characterized by using a polyphasic taxonomic approach. The predominant cellular fatty acids of strain 1NDH52 T were summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c) and C 14:0 2-OH; the major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid; the major respiratory quinones were Q-10 and Q-9. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 1NDH52 T belonged to the genus Croceicoccus with high similarities to the close type strains Croceicoccus pelagius Ery9 T , Croceicoccus sediminis S2-4-2 T and Croceicoccus bisphenolivorans H4 T . Phylogenomic analysis indicated that strain 1NDH52 T formed an independent branch distinct from the known type strains of this genus. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain 1NDH52 T and the three type strains above were well below thresholds of 70% DDH and 95-96% ANI for species denition, implying that strain 1NDH52 T should represent a novel genospecies. The genomic DNA G + C content was 62.6%. The carotenoids production of the novel strain was determined by the detection of the pigment absorption spectrum and the identication of the complete biosynthetic gene cluster in its genome. Based on the phenotypic and genotypic characteristics, strain 1NDH52 T is concluded to represent a novel species of the genus Croceicoccus, for which the name Croceicoccus gelatinilyticus sp. nov., is proposed. The type strain of the species is 1NDH52 T (= GDMCC 1.2381 T = KCTC 82668 T ). The description of the genus Croceicoccus has also been emended. Ningde, was used to isolate sterilized and spread on MA medium. at 28 °C for a week, were picked out on and on the new MA medium. A bacterial strain designated as 1NDH52 T was isolated and subjected to the taxonomic analysis. The strain was stored in 20% (v/v) glycerol suspension and maintained at -80 °C for long-term preservation. The three phylogenetically close type strains C. sediminis S2-4-2 T (= MCCC 1K03706 T ), C. pelagius Ery9 T (= MCCC 1A02459 T ) and C. bisphenolivorans H4 T (= MCCC 1K02301 T ) were obtained from the Marine Culture Collection of China (MCCC). In this study, the morphological, physiological and chemotaxonomic tests of strain 1NDH52 T and the three strains were performed MA medium or in marine broth 2216 (MB; BD Difco) under the same conditions unless otherwise specied. aqueous hydrogen peroxide solution and oxidation of 1% (w/v) N,N,N',N'-tetramethyl-1,4-phenylenediamine, respectively. Growth was evaluated at various temperatures (4, 10, 15, 20, 28, 32, 37, 40, 43, 45 and 50 °C) on the MA medium for four weeks. The growth pH range and optimum pH were determined in the MB broth adjusted to pH 4.0-11.0 (at increments of 1 pH units) with citrate/phosphate (pH 4.0-7.0), Tris/HCl (pH 8.0-9.0) or sodium carbonate/sodium bicarbonate (pH 10.0-11.0) buffers. Tolerance to NaCl was performed in articially modied MB broth supplemented with NaCl concentrations of 0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10% (w/v). Substrate hydrolysis was tested by using the MB medium as the basal medium supplemented with 1% soluble starch, 1% skimmed milk, 1% carboxymethyl cellulose and 1% Tweens 20, 40, 60 and 80, respectively. The hydrolysis of these substrates was determined according to the previously described methods (Liu et al. 2021a). Additional enzyme activities and biochemical properties were examined by using API ZYM and API 20NE strips following the manufacturer’s instructions. the existence of gene markers specic to class Sphingomonadales relatedness indices DNA-DNA hybridization average nucleotide identity genome-to-genome distance calculator version 2.1 online service recommended 2 version 2018), Gene prediction annotation genomes strain 1NDH52 type strains default parameters. tree reconstructed and in NaCl (optimum, 2%, w/v), and LB, and NA no casein and carboxymethyl cellulose. Hydrolysis of Tweens and the API ZYM strain 1NDH52 shows positive results for trypsin, α-chymotrypsin, α-galactosidase, β-galactosidase, β-glucuronidase, α-glucosidase, N-acetyl-β-glucosaminidase, α-mannosidase and α-fucosidase; negative for alkaline phosphatase, esterase (C4), esterase lipase (C8), lipase (C14), leucine arylamidase, valine arylamidase, cystine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase and β-glucosidase. In the API 20NE tests, strain 1NDH52 T shows positive results for nitrate reduction, indole production, D-glucose fermentation, arginine dihydrolase, urease, β-galactosidase, utilization of D-glucose, D-mannose and phenylacetic acid; negative results for nitrite reduction, β-glucosidase, gelatin hydrolysis, utilization of L-arabinose, D-mannitol, N-acetyl-glucosamine, D-maltose, potassium gluconate, capric acid, adipic acid, malic acid and trisodium citrate. The predominant cellular fatty acids are summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c,) and C 14:0 2-OH. The major polar lipids are diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamin, phosphatidylglycerol, and sphingoglycolipid.


Introduction
The genus Croceicoccus, a member of the family Erythrobacteraceae of the class Alphaproteobacteria, was proposed and initially contained only a species, Croceicoccus marinus (Xu et al. 2009). According to the latest List of Prokaryotic Names with Standing in Nomenclature (https://lpsn.dsmz.de/genus/croceicoccus) (Parte 2018), there are currently seven species with validly published names, including Croceicoccus marinus (Xu et al. 2009), Croceicoccus naphthovorans (Huang et al. 2015), Croceicoccus pelagius (Wu et al. 2016), Croceicoccus mobilis (Wu et al. 2016), Croceicoccus ponticola (Park et al. 2019), Croceicoccus sediminis (Huang et al. 2020) and Croceicoccus bisphenolivorans (Li et al. 2021). Taxonomically, the genus Croceicoccus is characterized as Gram-staining-negative, aerobic, yellow-pigmented, and coccoid or rod-shaped bacteria (Xu et al. 2009). The cellular predominant fatty acids of this genus bacteria were summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c) and the major respiratory quinone was ubiquinone 10 (Q-10). Croceicoccus have been frequently isolated from diverse marine environments, such as surface seawater from the Atlantic Ocean (Wu et al. 2016) and South Korea (Lee et al. 2018), the coastal sediment from Quanzhou Bay, Fujian (Huang et al. 2020) and the deep-sea sediment from the East Paci c polymetallic nodule region (Xu et al. 2009), the bio lm on a boat shell in the harbor of Zhoushan island, Zhejiang Province, P. R. China (Huang et al. 2015), showing their wide adaptability.

Isolation and culture of Croceicoccus strains
To investigate the culturable bacterial diversity of coastal areas, a sediment sample was obtained from the tidal at (26°44'02.7″ N, 119°48'32.0″ E) in Ningde, Fujian province, P. R. China. Marine agar 2216 (MA; BD Difco) medium was used to isolate bacteria. The sample was serially diluted with sterilized water and spread on MA medium. After incubation at 28 °C for a week, colonies were picked out based on their characteristics and then streaked on the new MA medium. A bacterial strain designated as 1NDH52 T was isolated and subjected to the taxonomic analysis. The strain was stored in 20% (v/v) glycerol suspension and maintained at -80 °C for long-term preservation. The three phylogenetically close type strains C. sediminis S2-4-2 T (= MCCC 1K03706 T ), C.
pelagius Ery9 T (= MCCC 1A02459 T ) and C. bisphenolivorans H4 T (= MCCC 1K02301 T ) were obtained from the Marine Culture Collection of China (MCCC). In this study, the morphological, physiological and chemotaxonomic tests of strain 1NDH52 T and the three strains were performed MA medium or in marine broth 2216 (MB; BD Difco) under the same conditions unless otherwise speci ed.

Phenotypic and biochemical characteristics
The morphological characteristics of colonies and cells of strain 1NDH52 T were examined by the stereomicroscope (SZX10, Olympus) and the transmission electron microscope (H7650, Hitachi) by using cultures on the MA medium for 48 h according to the instruments' manuals, respectively. Motility was tested in MB broth supplemented with 0.5% agar. Growth of strain 1NDH52 T and the three reference type strains was tested at 28 °C on the R2A agar, nutrient agar (NA), Luria-Bertani agar (LB) and tryptic soy agar (TSA) media for four weeks. Anaerobic growth of strain 1NDH52 T was tested in an anaerobic pouch (MGC, Mitsubishi) on MA medium at 28 °C for four weeks. Gram staining was performed by using a Gram-stain kit (HKM) according to the manufacturer's instructions. Catalase and oxidase activities were assessed through bubble production in 10% (v/v) aqueous hydrogen peroxide solution and oxidation of 1% (w/v) N,N,N',respectively. Growth was evaluated at various temperatures (4,10,15,20,28,32,37,40,43,45 and 50 °C) on the MA medium for four weeks. The growth pH range and optimum pH were determined in the MB broth adjusted to pH 4.0-11.0 (at increments of 1 pH units) with citrate/phosphate (pH 4.0-7.0), Tris/HCl (pH 8.0-9.0) or sodium carbonate/sodium bicarbonate (pH 10.0-11.0) buffers. Tolerance to NaCl was performed in arti cially modi ed MB broth supplemented with NaCl concentrations of 0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10% (w/v). Substrate hydrolysis was tested by using the MB medium as the basal medium supplemented with 1% soluble starch, 1% skimmed milk, 1% carboxymethyl cellulose and 1% Tweens 20, 40, 60 and 80, respectively. The hydrolysis of these substrates was determined according to the previously described methods (Liu et al. 2021a). Additional enzyme activities and biochemical properties were examined by using API ZYM and API 20NE strips following the manufacturer's instructions.

Chemotaxonomic characterization
For the analysis of cellular fatty acids, cells of strain 1NDH52 T and the three reference type strains were collected from the third quadrant on MA medium at 28°C . The harvested cells were saponi ed, methylated and extracted according to the protocol of the Sherlock Microbial Identi cation System (MIDI). The prepared fatty acids were analyzed by gas chromatography (model 7890B; Agilent) using the Microbial Identi cation software package with the Sherlock MIDI 6.1 system and the Sherlock Aerobic Bacterial Database (TSBA 6.1). Polar lipids were extracted by using the chloroform/methanol system (Minnikin et al. 1984) and separated by two-dimensional thin-layer chromatography (Silica gel 60 F254, Merck). The plates dotted with the sample were subjected to twodimensional development, with the rst solvent of chloroform-methanol-water (65:25:4, v/v) followed by the second solvent of chloroform-methanol-acetic acid-water (85:12:15:4, v/v). The extracted lipids were identi ed by spraying with 10% ethanolic molybdophosphoric acid, ninhydrin, molybdenum blue, αnaphthol-sulphuric acid and Dragendorff's reagent. The respiratory quinone was extracted and determined by using the high-performance liquid chromatography (Agilent 1200; ODS 250×4.6 mm×5 µm; owing phase, methanol-isopropanol, 2: 1; 1 mL·min -1 ) according to the method described by Collins et al. (1977).
Sequencing and phylogenetic analysis of the 16S rRNA gene Genomic DNA of strain 1NDH52 T was extracted from fresh cells by using the HiPure Bacterial DNA Kit (Magen Biotech Co., Ltd.) following the manufacturer's instructions. The 16S rRNA gene was ampli ed using universal bacterial primers 27F and 1492R (Weisburg et al. 1991) with the PCR MasterMix (G-clone (Beijing) Biotech Co., Ltd.) in a 50 μL PCR system. PCR products were sequenced by Suzhou Genewiz Biotechnology Co., Ltd. (Suzhou, P. R. China). The sequences were assembled by using the software DNAMAN version 8 (Lynnon Biosoft, www.lynnon.com). The 16S rRNA gene sequences of related taxa were obtained from the EzBioCloud (www.ezbiocloud.net) (Yoon et al. 2017) and NCBI databases. Multiple sequence alignment was performed by using the software MAFFT version 7.037 under the L-INS-i interative re nement (Katoh and Standley 2014). Pairwise identities of 16S rRNA gene sequences were calculated by using DNAMAN. Phylogenetic tree based on 16S rRNA gene sequences was reconstructed by using the software IQ-TREE version 2.1.2 (Minh et al. 2020) based on the maximum likelihood (ML) method (Felsenstein 1981) under the K2P + I + G4 nucleotide substitution model, which was selected by the ModelFinder (Kalyaanamoorthy et al. 2017). Support for the inferred ML tree was inferred by the ultrafast bootstrapping with 10,000 replicates (Hoang et al. 2018). The visualization and annotation of the resulting phylogenetic tree were performed by using the software MEGA version X (Kumar et al. 2018) The type strain Altericroceibacterium indicum MSSRF26 T was used as an outgroup in all phylogenetic analyses.

Genome sequencing, overall genome relatedness indices and phylogenomic analysis
The genome sequence of strain 1NDH52 T was determined by using the Illumina Novaseq PE150 platform of Shanghai Majorbio Bio-Pharm Technology Co., Ltd. About 1 Gbp of clean data for strain 1NDH52 T was generated, reaching 200-fold coverage. The high-quality reads were assembled by using the software SPAdes version 3.8.1 with default parameters (Bankevich et al. 2012). The available genomes of the three close type strains and other related type strains within the family Erythrobacteraceae were obtained from the GenBank database. All genomes used in this study were assessed by using the software CheckM version 1.1.2 (Parks et al. 2015), which inspected the existence of gene markers speci c to the class Sphingomonadales (UID3310). Overall genome relatedness indices (OGRIs) including digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) were estimated by using the genome-togenome distance calculator version 2.1 online service with the recommended formula 2 (Auch et al. 2010) and the software FastANI version 1.31 (Jain et al. 2018), respectively. Gene prediction and annotation of genomes of strain 1NDH52 T and the close type strains were performed by using the software Prokka version 1.13 (Seemann 2014) and the fully automated Rapid Annotation using Subsystem Technology (RAST) pipeline (Overbeek et al. 2014) with default parameters. The functional roles of annotated genes for each genome were assigned and grouped in subsystem feature categories. The phylogenomic tree was reconstructed based on an up-to-date 92 bacterial core gene sets by the software UBCG version 3.0 (Na et al. 2018) with default parameters.

Determination of the pigment and the biosynthetic genes
The genus Croceicoccus is characterized by carotenoid biosynthesis (Xu et al. 2009). Therefore, the pigment absorption spectrum was performed according to the method described by Liu et al. (2021b). Cultures in the exponential phase of growth were scraped from the MA medium plates and then the cell pellet was mixed with 5 mL acetone/methanol (1:1, v/v) and incubated in the dark at 28 ℃ for an hour. The cell suspensions were centrifuged at 8000 g for 10 min and ltrated by a 0.22-μm organic phase needle lter after incubation in acetone/methanol. The absorption spectrum of the supernatant was monitored with a Lambda 45 UV/VIS spectrophotometer (Perkin Elmer). The genes related to the carotenoid biosynthesis among strain 1NDH52 T and related type strains were determined and compared based on the genome annotation by the RAST.

Nucleotide sequences
The GenBank/EMBL/DDBJ accession numbers of 16S rRNA gene and genome sequences of strain 1NDH52 T are MZ165339 and JAHCBF000000000, respectively.

Results And Discussion
Morphological and physiological characterization Colonies of strain 1NDH52 T were yellow-colored, circular, convex and smooth with a diameter of about 2 mm after cultivation on MA medium at 28 °C for 48 h (Fig. S1a). Cells of the strain were observed to be Gram-staining-negative and rod-shaped (0.5 μm wide and 1.0-1.2 μm long, Fig. S1b). Its activities of catalase and oxidase were positive. Anaerobic growth was not observed on MA medium. As listed in Table 1, the ranges of temperature, pH and NaCl for growth of strain 1NDH52 T were 10-40 °C, 7.0-10.0 and 1-8% (w/v), and the optima of them were 28 °C, 7.0-8.0 and 2.0% (w/v) NaCl. Strain 1NDH52 T could not grow on TSA medium, but the two type strains C. pelagius Ery9 T and C. bisphenolivorans H4 T could do. Strain 1NDH52 T could be also distinguished from C. sediminis S2-4-2 T , C. pelagius Ery9 T and C. bisphenolivorans H4 T by the hydrolysis of Tweens 40 and 60. Differential physiological and biochemical characteristics between strain 1NDH52 T and the related reference strains were shown in Table 1. In the API ZYM and API 20NE tests, strain 1NDH52 T could be distinguished from the three close relatives by the utilization of some carbohydrates, lipase (C14) and cystine arylamidase. Additional phenotypic characteristics that served to differentiate strain 1NDH52 T from the three reference strains are shown in Table 1 and the species description.

Chemotaxonomic characterization
The fatty acid compositions of strain 1NDH52 T and the three close type strains are listed in Table 2. The major fatty acids (> 10% of total fatty acids) of strain 1NDH52 T were summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c, 57.4%) and C 14:0 2-OH (12.3%), and the minor fatty acids (> 5%) was C 16:0 (5.7%). As showed in Table 2, the fatty acids pro le of strain 1NDH52 T was in agreement with those of the three type strains, but strain 1NDH52 T was distinguishable from the three reference strains by the proportions of some fatty acids, such as iso-C 14:0 , iso-C 15:0 and iso-C 16:1 2-OH. The polar lipids of strain 1NDH52 T were diphosphatidylglycerol (DPG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), sphingoglycolipid (SGL), an unidenti ed glycolipid (GL) and two unidenti ed lipids (L1-2) (Fig. S2). As shown in Table 1, strains 1NDH52 T exhibited similar polar lipid pro les to almost all type strains of this genus with the PC, PE, PG and SGL as major components. An obvious difference was that strains 1NDH52 T and C. ponticola GM-16 T contained the DPG, but the others did not. The major respiratory quinones of strain 1NDH52 T were Q-10 (83.8%), Q-9 (13.9%), and the minor quinone was Q-8 (2.3%) (Fig.  S3), which was different from other related type strains.
Phylogenetic analysis based on 16S rRNA gene The almost complete 16S rRNA gene sequence of strain 1NDH52 T (1347 bp) was determined by the Sanger sequencing. Its complete 16S rRNA gene sequence (1489 bp, locus_tag="KIH45_RS18855") from its genome sequence as shown below shared a 100% similarity with that by the PCR. In this case, the complete 16S rRNA gene sequence of strain 1NDH52 T was used for the following analysis. The sequence comparison by using the BLAST and EzBioCloud search results showed that strain 1NDH52 T belonged to the genus Croceicoccus with similarities to C. pelagius Ery9 T (98.7%), C. sediminis S2-4-2 T (98.9%) and C. bisphenolivorans H4 T (99.2%). The ML phylogenetic tree based on 16S rRNA gene sequences showed that strain 1NDH52 T clustered together with type strain C. sediminis S2-4-2 T with 72% bootstrap value ( Fig. 1), indicating the close relationship with each other. Furthermore, strain 1NDH52 T formed a separate branch different from all type strains of recognized species of the genus Croceicoccus. The 16S rRNA gene sequence-based analyses indicated that strain 1NDH52 T may represent a member of a putative novel species of the genus Croceicoccus.

Comparative genomics and phylogenomic analysis
The general genome characteristics of strain 1NDH52 T and the related type strains are shown in Table 3. Based on the estimation from the CheckM, all genomes were determined to be of high quality based on their higher than 98% completeness and less than 2.5% contamination (Table 3) (Parks et al. 2015).
The genome sizes of strains 1NDH52 T and other type strain were from 3,001,363 to 4,116,752 bp. The genome size of strains 1NDH52 T was 3,790,455 bp and only lower than strain C. mobilis Ery22 T with 4,116,752 bp. The genomic sequence of strain 1NDH52 T contained 3800 genes, 3 rRNA genes and 50 tRNA genes. The genomic DNA G + C content of strain 1NDH52 T was 62.6% and under the range from 62.1 to 65.2% for the genus Croceicoccus (Table 3). Besides, the two 16S rRNA gene sequences of strain 1NDH52 T respectively from the PCR and its genome by using a local BLAST sharing 100% identity con rmed the authenticity of the nal genome assembly again.
In recent years, genomic information has increasingly been used for prokaryotic species de nition and classi cation (Chun et al. 2018). The two OGRIs including dDDH and ANI were conducted in this study. The dDDH and ANI values between strain 1NDH52 T and the three close type strains C. pelagius Ery9 T , C.
Therefore, the comprehensive analyses of OGRIs and genome-based phylogeny indicated that strain 1NDH52 T should represent a novel genospecies of the genus Croceicoccus.
Based on the genome annotation of RAST, the sub-system category distribution of 1NDH52 T and the seven related type strains was compared. As shown in Table S1, strain 1NDH52 T has 1321 annotated genes, accounting for 34.8% of the whole genome, most of which are necessary for bacterial survival, such as DNA, RNA, protein, amino acids and derivatives, fatty acids, lipids and isoprenoids, and carbohydrates metabolism. The similar distribution pattrens of key metabolic-related genes were found in other type strains. Strain 1NDH52 T and the seven type strains presented some unique features related to nitrogen metabolism, gene transfer agent, protein and nucleoprotein secretion system, cAMP signaling, iron acquisition, and metabolism. Among them, strain 1NDH52 T contained genes encoding nitrate reductase, indicating that it could reduce nitrate, which was also con rmed by the nitrate reduction test in the API 20NE, but type strains C. sediminis S2-4-2 T and C. ponticola GM-16 T did not; strain 1NDH52 T contained genes encoding type IV protein secretion systems, but type strain C. pelagius Ery9 T did not. Instead, the reference type strains contained genes related to the ton and tol transport systems, but strain 1NDH52 T did not.

The determination of the pigment and related genes
The result showed that the acetone-methanol-soluble pigment was characterized by the two maximum absorption peaks at 450 and 478 nm, suggesting that strain 1NDH52 T could produce carotenoid ( Figure S4a). As shown in Figure S4b and Table S2, all key genes including crtB, crtI, crtY, crtG, crtE and crtZ related to the carotenoid biosynthesis were identi ed in strain 1NDH52 T and other close relatives based on the genomic annotation and the local BLAST.

Conclusion
Strain 1NDH52 T showed consistent chemotaxonomic traits characterized by the genus Croceicoccus, such as summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c) and C 14:0 2-OH as the predominant fatty acids, DPG, PC, PE, PG and SGL as major polar lipids, Q-10 as the dominant respiratory quinone. Moreover, the microorganism can be distinguished from the three close type strains by using a combination of the phylogenetic analysis based on 16S rRNA gene and genome sequences and phenotypic properties, such as the gelatin hydrolysis, the utilization of some carbohydrates and no growth on TSA medium. Therefore, strain 1NDH52 T is considered to represent a novel species of the genus Croceicoccus, for which the name Croceicoccus gelatinilyticus sp. nov. is proposed. As a consequence of the newly reported characteristics not included in the original and emended descriptions of the genus Croceicoccus (Xu et al. 2009;Huang et al. 2015), the description of this genus has been emended. Colonies of strain 1NDH52 T were yellow, circular, convex and smooth with a diameter of 2 mm after cultivation on MA medium at 28 °C for 48 h. The activities of catalase and oxidase are positive. No anaerobic growth occurs on MA medium. Growth at 10-40 °C (optimum, 28 °C), at pH 7.0-10.0 (optimum, 7.0-8.0) and in 1-8% NaCl (optimum, 2%, w/v), and on R2A, LB, MA and NA media; no growth on TSA media. Do not hydrolyze the skimmed milk, Tweens 20 and 80, starch, casein and carboxymethyl cellulose. Hydrolysis of Tweens 40 and 60. In the API ZYM tests, strain 1NDH52 T shows positive results for trypsin, α-chymotrypsin, α-galactosidase, β-galactosidase, β-glucuronidase, α-glucosidase, N-acetyl-β-glucosaminidase, α-mannosidase and α-fucosidase; negative for alkaline phosphatase, esterase (C4), esterase lipase (C8), lipase (C14), leucine arylamidase, valine arylamidase, cystine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase and β-glucosidase. In the API 20NE tests, strain 1NDH52 T shows positive results for nitrate reduction, indole production, D-glucose fermentation, arginine dihydrolase, urease, β-galactosidase, utilization of D-glucose, D-mannose and phenylacetic acid; negative results for nitrite reduction, βglucosidase, gelatin hydrolysis, utilization of L-arabinose, D-mannitol, N-acetyl-glucosamine, D-maltose, potassium gluconate, capric acid, adipic acid, malic acid and trisodium citrate. The predominant cellular fatty acids are summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c,) and C 14:0 2-OH. The major polar lipids are diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamin, phosphatidylglycerol, and sphingoglycolipid. The major respiratory quinones are ubiquinones 10 and 9 and the minor quinone is ubiquinones 8.
The type strain, 1NDH52 T (= GDMCC 1.2381 T = KCTC 82668 T ), was isolated from the tidal at sediment in Ningde city, Fujian province, P. R. China. The genomic DNA G + C content of the type strain is 62.6%.
Emended description of the genus Croceicoccus Xu et al. 2009 andHuang et al. 2015 In addition to the characteristics reported by Xu et al. (2009) andHuang et al. (2015), the following properties of the genus Croceicoccus are observed. The polar lipids contain diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, glycolipid, phospholipid and lipid. Besides the major respiratory ubiquinone 10, some species contain ubiquinones 9 and 8. The genomic DNA G + C contents range from 62.1 to 65.2%.
Fatty acids 1NDH52 T C. sediminis S2-4-2 T C. pelagius Ery9 T C. bisphenolivorans H4 T Data on the fatty acids of all strains were obtained from this study. Values were percentages of total fatty acids. Less than 0.5% and/or the absence of fatty acids for all strains were not shown. The predominant cellular fatty acids for all strains (> 10%) were in bold. TR, trace amount (< 0.5%); ND, not detected. # , summed features are fatty acids that cannot be resolved reliably from another fatty acid using the chromatographic conditions chosen. The MIDI system groups these fatty acids together as one feature with a single percentage of the total. The summed feature 3, C 16:1 ω6c and/or C 16:1 ω7c; summed feature 8, C 18:1 ω6c and/or C 18:1 ω7c.