Production and Properties of Alkaline Dextranase from a Newly Isolated Brevibacterium

About 500 strains of dextranase producing microorganisms were examined in detail for pH- activity and enzyme stability. A gram positive bacterium identified as belonging to the genus Brevibacterium was found to produce alkaline dextranase. Maximal dextranase synthesis was obtained when grown aerobically at 26°C for 3 days in a medium containing 1 % dextran, 2% ethanol, 1 % polypeptone and 0.05 % yeast extract together with trace amounts of inorganic salts.

Brevibacterium dextranase had an optimum pH of 8.0 for activity at 37°C and an optimal temperature at 53°C at pH 7.5. The enzyme was quite stable over the range of pH 5.0 to 10.5 on 24 hr incubation at 37°C, especially on alkaline pH. The enzyme was also heat stable at 60°C for 10 min.     

Extracellular Production of l-Lysine α-Oxidase in Wheat Bran Culture of a Strain of Trichoderma viride

A mold strain Y244-2 capable of producing l-lysine α-oxidase, a new enzyme catalyzing the α-oxidative deamination of l-lysine, was identified as Trichoderma viride. Among strains belonging to the genus Trichoderma tested, only Trichoderma viride Y244-2 produced the enzyme in wheat bran culture. The maximum enzyme production by the mold grown on wheat bran was observed after 10 and 14 days incubation with and without NaN0₃, respectively. Addition of NaN0₃, NH₄N0₃, adenine, purine nucleosides, l-histidine, glycine or l-glutamine to wheat bran stimulated the production of the enzyme. In the liquid culture, the enzyme was produced extracellulary under the aerobic conditions, although the production was much lower than that in the wheat bran culture.     

Penicillium notatum 1 a new source of dextranase

Summary Two hundred and fifteen fungal strains were screened for extracellular dextranase production with a diffusion plate method. The best enzymatic activity (12–19 DU ml^–1) was achieved byPenicillium notatum 1, a species for which the dextranase productivity has not yet been published. Some of the parameters affecting enzyme production have been standardized. The enzyme in crude state was relatively stable, its maximal activity was at 50°C and at pH 5.0. Conidia of the selected strain were mutagenized, and isolated mutants were tested for production of dextranase in submerged culture. The most active mutant,P. notatum 1-I-77, showed over two-times higher dextranase activity than the parentP. notatum 1     

南海东海岛近海固氮细菌多样性及对菜心的促生作用

海洋固氮细菌在自然界氮循环中发挥着重要作用,筛选和开发海洋固氮促生的菌种资源,对于生物菌肥的开发应用和农业生产具有重要意义。[目的]研究海洋固氮细菌的生物多样性及对陆地作物的促生作用,筛选优良的植物根际促生菌株。[方法]通过形态特征、生理生化试验和16S rRNA基因序列比对进行菌属鉴定;将解磷、解钾、产蛋白酶和纤维素酶等性能优良的菌株作为菜心盆栽试验的组合菌液,探究对菜心能否起促生作用。[结果]本研究从南海东海岛的海岛沉积物中筛选出18株固氮菌,分布在6个属9种,不动杆菌属4株,假交替单胞菌属1株,芽孢杆菌属8株,嗜冷杆菌属1株,海单胞菌属1株,交替单胞菌属3株。菜心幼苗经过组合菌剂的浇灌,在茎高、茎粗、最大叶宽和最大叶长4个指标均表明对菜心有显著的促生作用。其中,以芽孢杆菌属和不动杆菌属的菌株在菜心的生长过程中起关键的促进作用,对菜心的促生性能最佳。[结论]南海近海具有种类丰富多样的固氮细菌,以芽孢杆菌属和不动杆菌属的菌株促生作用最为显著,具有开发成微生物菌肥的潜力,为优良的海洋促生微生物菌种资源的定向利用及蔬菜的无公害生产提供重要依据。     

Purification and characterization of a dextranase from Sporothrix schenckii

A dextranase (EC 3.2.1.11) was purified and characterized from the IP-29 strain of Sporothrix schenckii, a dimorphic pathogenic fungus. Growing cells secreted the enzyme into a standard culture medium (20 °C) that supports the mycelial phase. Soluble bacterial dextrans substituted for glucose as substrate with a small decrease in cellular yield but a tenfold increase in the production of dextranase. This enzyme is a monomeric protein with a molecular mass of 79 kDa, a pH optimum of 5.0, and an action pattern against a soluble 170-kDa bacterial dextran that leads to a final mixture of glucose (38%), isomaltose (38%), and branched oligosaccharides (24%). In the presence of 200 mM sodium acetate buffer (pH 5.0), the K _m for soluble dextran was 0.067 ± 0.003% (w/v). Salts of Hg²⁺, (UO₂)²⁺, Pb²⁺, Cu²⁺, and Zn²⁺ inhibited by affecting both V _max and K _m. The enzyme was most stable between pH values of 4.50 and 4.75, where the half-life at 55 °C was 18 min and the energy of activation for heat denaturation was 99 kcal/mol. S. schenckii dextranase catalyzed the degradation of cross-linked dextran chains in Sephadex G-50 to G-200, and the latter was a good substrate for cell growth at 20 °C. Highly cross-linked grades (i.e., G-10 and G-25) were refractory to hydrolysis. Most strains of S. schenckii from Europe and North America tested positive for dextranase when grown at 20 °C. All of these isolates grew on glucose at 35 °C, a condition that is typically associated with the yeast phase, but they did not express dextranase and were incapable of using dextran as a carbon source at the higher temperature. Received: 29 December 1997 / Accepted: 4 March 1998     

Transient Accumulation of Metabolic Intermediates of p-Cresol in the Culture Medium by a Pseudomonas sp. Strain A Isolated from a Sewage Treatment Plant

Summary Activated sludge from a sewage treatment plant in Kanpur, India, was screened for bacterial strains metabolizing p-cresol exclusively under aerobic conditions. One such isolate was identified to be belonging to the genus Pseudomonas based on morphological and physiological criteria as well as 16S ribosomal RNA gene sequence analysis. Two intermediates were identified from the culture medium during the growth phase of Pseudomonas sp. strain A that indicated that the strain degraded p-cresol via the protocatechuate (PCA) pathway. p-Cresol was rapidly converted into p-hydroxybenzaldehyde (PHB) during early growth phase, which was later utilized after p-cresol depletion. p-Hydroxybenzoate (PHBA) accumulation was observed during the later stages of exponential growth phase. Kinetic constants for the degradation of p-cresol were determined using Haldane’s model. High μ_max and inhibitory constant (K_I) values along with the observed accumulation of significant amounts of PHB in culture filtrates seem to indicate that the isolated Pseudomonas sp. strain A may be of potential use in biotransformations.     

OBSERVATIONS SUR LES BESOINS EN VITAMINES DES DESMIDIÉES (CHLOROPHYCÉES-ZYGNEMATALES)1

The minimal nutrient requirements of 61 strains of desmids belonging to 18 different genera were investigated within 16 axenic cultures and 45 contaminated cultures. Thirty-nine strains were autotrophic: they included all 30 strains belonging to the genera Cosmarium, Staurastrum, and Micrasterias. Twenty-two strains were auxotrophic; they included all 14 strains belonging to the genus Closterium. Of the 22 auxotrophic strains, 13 required only vitamin B₁₂; the specific requirements of the other 9 strains were not determined.     

Gas Chromatographic Analysis of Volatile Esters in Wines

We isolated a new aerobic gram negative collagenolytic bacterium, strain CRZV₁. This strain is yellow pigmented, non motile; it poorly degrades the sugars and its proteolytic activity corresponds to one enzyme, a collagenase which is produced in media with collagen, or collagen like substrates. The strain CRZV_l, presents many similarities with Flavobacteria. However, the GC content of the DNA, which is 65%, excludes our collagenolytic strain from the genus Flavobacterium, where all the species have GC content between 30 and 42%. All the strains, already described as Flavobacteria, the GC contents of which are situated between 55 and 70%, are actually unclassified. They could be included in the genus Empedobacter. This genus is not in the approved list of bacterial names, so we only consider this new collagenolytic bacteria as a gram negative, aerobic, yellow pigmented bacteria.     

Dextranase production by recombinant Pichia pastoris under operational volumetric mass transfer coefficient (kLa) and volumetric gassed power input (Pg/V) attainable at commercial large scale

Abstract

Most of the reported bioprocesses carried out by the methylotrophic yeast Pichia pastoris have been performed at laboratory scale using high power inputs and pure oxygen, such conditions are not feasible for industrial large-scale processes. In this study, volumetric mass transfer (k_La) and volumetric gassed power input (Pg/V) were evaluated within values attainable in large-scale production as scale-up criteria for recombinant dextranase production by Mut^S P. pastoris strain. Cultures were oxygen limited when the volumetric gassed power supply was limited to 2?kW m^?3. Specific growth rate, and then dextranase production, increased as k_La and Pg/V did. Meanwhile, specific production and methanol consumption rates were constant, due to the limited methanol condition also achieved at 2?L bioprocesses. The specific dextranase production rate was two times higher than the values previously reported for a Mut⁺ strain. After a scale-up process, at constant k_La, the specific growth rate was kept at 30?L bioprocess, whereas dextranase production decreased, due to the effect of methanol accumulation. Results obtained at 30?L bioprocesses suggest that even under oxygen-limited conditions, methanol saturated conditions are not adequate to express dextranase with the promoter alcohol oxidase. Bioprocesses developed within feasible and scalable operational conditions are of high interest for the commercial production of recombinant proteins from Pichia pastoris.     

Lysinoalanine Formation in Gluten: A Conformational Effect

The production of pectolytic enzyme in the genus Kluyveromyces was investigated. The production of the enzyme was dependent on the strain, and some strains belonging to K. fragilis, K. Marxianus, and K. Wickerhamii produced this enzyme among 11 species (29 strains) of the genus Kluyveromyces. K. Fragilis IFO 0288 produced at least four endo-polygalacturonases which have different molecular weights. The dominant endo-polygalacturonase in the culture filtrate of the strain was purified and isolated as crystals. The purified enzyme was homogeneous based on analysis by polyacrylamide gel electrophoresis and ultracentrifugation. The enzyme was a glycoprotein having an isoelectric point around pH 5.6. The sedimentation coefficient (s_2o,w) was 3.77S, and the molecular weight was around 33,000. The enzyme contained aspartic acid (asparagine), serine,threonine, and glycine at relatively high levels. The enzyme showed the highest activity around pH 5.0 and was stable at pH 5.0 up to 30°C. With the enzyme, and activity which releases highly polymerized pectin from various protopectins (protopectinase activity) was found.     

Cloning and expression of Penicillium minioluteum dextranase in Saccharomyces cerevisiae and its exploitation as a reporter in the detection of mycotoxins

A dextranase gene from Penicillium minioluteum (strain IMI068219) has been cloned, sequenced and expressed in Saccharomyces cerevisiae via fusion of the DNA segment encoding the mature dextranase protein with α-factor signal sequence, and insertion into the GAL1–controlled expression vector pYES2/CT. Galactose-induced expression yielded extracellular dextranase activity of 0.63 units/ml and cell-associated dextranase activity of 0.48 units/ml, after 24 h incubation. The dextranase construct was introduced into a strain of S. cerevisiae expressing the human cytochrome P450 3A4 (CYP3A4) and the cognate reductase, which was then used to develop a microplate toxicity bioassay. Toxicity was signalled as inhibition of dextranase activity, assayed fluorimetrically. This novel bioassay was assessed using six economically significant mycotoxins.     

Diversity of the culturable lichen-derived actinobacteria and the taxonomy of Streptomyces parmotrematis sp. nov.

A total of 37 actinobacteria were isolated from eighteen lichen samples collected in Thailand. Based on the 16S rRNA gene sequences, they were identified into five genera including Actinoplanes (1 strain), Actinomadura (1 strain), Pseudosporangium (1 strain), Wangella (1 strain) and Streptomyces (33 strains). Among these isolates, strain Ptm05^T, Ptm01 and Ptm12 showed low 16S rRNA gene similarity and was selected for the further taxonomic study using the polyphasic approach. These strains showed the highest 16S rRNA gene sequence similarity with Streptomyces sparsogenes ATCC 25498^T (97.44–97.72%). Strain Ptm05^T was selected for the type strain. The chemical cell composition of the strain was similar to the members of Streptomyces genus. LL-diaminopimelic acids were detected in the peptidoglycan. Menaquinones were MK-9(H₈) and MK-9(H₆). Phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, one unidentified phospholipid, one unidentified glycolipid and one unidentified lipid were detected as the polar lipids. The predominant cellular fatty acids are anteiso-C_15:0, iso-C_15:0, iso-C_16:0, iso-C_17:0 and C_16:0. The dDNA-DNA hybridization values among strain Ptm05^T and its closely related Streptomyces type strains were 17.2–18.0%. In addition, the ANIb and ANIm between strain Ptm05^T and related Streptomyces type strains were ranged from 75.69 to 76.13% and 85.21 to 85.35%, respectively. Based on phenotypic and genomic evidence, strain Ptm05^T (=?TBRC 14546^T?=?NBRC 115203^T) represents the novel species of the genus Streptomyces for which the name Streptomyces parmotrematis sp. nov. is proposed. This study showed that the lichens are the promising source of the novel actinobacterial taxa.

     

Diazotrophic bacilli isolated from the sunflower rhizosphere and the potential of Bacillus mycoides B38V as biofertiliser

The nitrogen fixation by strains belonging to the Bacillus genus remains poorly explored. In this work, the diversity of endospore‐forming bacilli isolated from the rhizosphere of sunflower was evaluated. A total of 101 strains were identified based on the V1‐V2 variable regions of the 16S rRNA gene. Strains belonging to the genera Bacillus and Paenibacillus represented 41.6% and 58.4%, respectively, of total isolates. The production of indolic compounds was a common trait among the isolates, and approximately 75% of them exhibited positive nitrogenase activity; but only 9.2% displayed activities higher than 1 nmol C₂H₄ mg protein h^?1. Within the genus Bacillus, the isolates related to the B. cereus group displayed the highest nitrogenase activity and were the second most frequent group of Bacillus sp. isolated. Plants inoculated with the isolate B38V showed the highest N content, and their shoot dry weights were significantly increased compared with positive control. Our results indicated that B38V, which belongs to the B. mycoides species, has the potential to promote sunflower growth. The data obtained in this study provide additional information concerning the diversity of Gram‐positive diazotrophic within the genera Bacillus and Paenibacillus and their potential for the biofertilisation of sunflower crops.     

Thermus sediminis sp. nov., a thiosulfate-oxidizing and arsenate-reducing organism isolated from Little Hot Creek in the Long Valley Caldera,California

Thermus species are widespread in natural and artificial thermal environments. Two new yellow-pigmented strains, L198^T and L423, isolated from Little Hot Creek, a geothermal spring in eastern California, were identified as novel organisms belonging to the genus Thermus. Cells are Gram-negative, rod-shaped, and non-motile. Growth was observed at temperatures from 45 to 75 °C and at salinities of 0–2.0% added NaCl. Both strains grow heterotrophically or chemolithotrophically by oxidation of thiosulfate to sulfate. L198^T and L423 grow by aerobic respiration or anaerobic respiration with arsenate as the terminal electron acceptor. Values for 16S rRNA gene identity (≤ 97.01%), digital DNA–DNA hybridization (≤ 32.7%), OrthoANI (≤ 87.5%), and genome-to-genome distance (0.13) values to all Thermus genomes were less than established criteria for microbial species. The predominant respiratory quinone was menaquinone-8 and the major cellular fatty acids were iso-C_15:0, iso-C_17:0 and anteiso-C_15:0. One unidentified phospholipid (PL1) and one unidentified glycolipid (GL1) dominated the polar lipid pattern. The new strains could be differentiated from related taxa by β-galactosidase and β-glucosidase activity and the presence of hydroxy fatty acids. Based on phylogenetic, genomic, phenotypic, and chemotaxonomic evidence, the novel species Thermus sediminis sp. nov. is proposed, with the type strain L198^T (= CGMCC 1.13590^T = KCTC XXX).

     

Paenibacillus sinensis sp. nov., a nitrogen-fixing species isolated from plant rhizospheres

Two strains HN-1^T and 39 were isolated from rhizospheres of different plants grown in different regions of PR China. The two strains exhibited high nitrogenase activities and possessed almost identical 16S rRNA gene sequences. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between the two strains were 99.9 and 99.8%, respectively, suggesting that they belong to one species. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strains HN-1^T and 39 are the members of the genus Paenibacillus and both strains exhibited 99.5% similarity to Paenibacillus stellifer DSM 14472^T and the both strains represented a separate lineage from all other Paenibacillus species. However, the ANI of type strain HN-1^T with P. stellifer DSM 14472^T was 90.69, which was below the recommended threshold value (<?95–96% ANI). The dDDH showed 42.1% relatedness between strain HN-1^T and P. stellifer DSM 14472^T, which was lower than the recommended threshold value (dDDH?<?70%). The strain HN-1^T contain anteiso-C_15:0 as major fatty acids and MK-7 as predominant isoprenoid quinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four aminophospholipids and an unidentified glycolipid. Unlike the most closely related P. stellifer DSM 14472^T, strain HN-1^T or 39 was positive for catalase reaction. Distinct phenotypic and genomic characterisations from previously described taxa support the classification of strains HN-1^T or 39 as representatives of a novel species of the genus Paenibacillus, for which the name Paenibacillus sinensis is proposed, with type strains HN-1^T (=CGMCC 1.18902, JCM 34,620), and reference strain 39 (=CGMCC 1.18879, JCM 34,616), respectively.

     

<Emphasis Type="Italic">Acinetobacter kyonggiensis</Emphasis> sp. nov., a <Emphasis Type="Italic">β</Emphasis>-glucosidase-producing bacterium,isolated from sewage treatment plant

A Gram-negative, non-motile bacterium, designated KSL5401-037^T, was isolated from a sewage treatment plant in Gwangju in the Republic of Korea and was characterized using a polyphasic taxonomic approach. Comparative 16S rRNA gene sequence analysis showed that strain KSL5401-037^T belonged to the genus Acinetobacter in the family Moraxellaceae of the Gammaproteobacteria (Brisou and Prevot, 1954). According to a 16S rRNA gene sequence analysis, it was closely related to Acinetobacter johnsonii ATCC 17909^T (97.3%), A. bouvetii 4B02^T (97.2%), and A. beijerinckii 58a^T (96.8%). Chemotaxonomic data revealed that strain KSL5401-037^T possesses an ubiquinone system with Q-8 as the predominant compound and C_16:0 (19.2%), C_18:1 ω9c (19.5%), and summed feature 3 (C_16:1 ω6c / C_16:1 ω7c, 34.1%) as the predominant cellular fatty acids. The major polar lipids detected in strain KSL5401-037^T were diphosphatidylglycerol (DPG) and, phosphatidylethanolamine (PE), followed by phosphatidylglycerol (PG) and moderate amounts of phosphatidylcholine and phosphatidylserine. The G+C content of the genomic DNA was 41.2–42.1 mol%. Strain KSL5401-037^T exhibited relatively low levels of DNA-DNA relatedness with respect to A. johnsonii DSM 6963^T (17.7%) and A. bouvetii 4B02^T (9.3%). The DNA-DNA relatedness values, biochemical, and physiological characteristics of strain KSL5401-037^T strongly support its genotypic and phenotypic differentiation from other recognized type strains of the genus Acinetobacter. Based on these data, strain KSL5401-037^T (JCM 17071^T =KEMC 5401-037^T) should be classified in the genus Acinetobacter as a type strain of novel species, for which the name Acinetobacter kyonggiensis sp. nov. is proposed.     

<Emphasis Type="Italic">Oceanobacillus manasiensis</Emphasis> sp. nov., a moderately halophilic bacterium isolated from the salt lakes of Xinjiang,China

Three Gram reaction positive, rod-shaped, moderately motile halophilic bacterial strains, designated YD3-56^T, YD16, and YH29, were isolated from the sediments of Manasi and Aiding salt lakes in the Xinjiang region of China, respectively. The strains grew optimally at 30–37°C, pH 8–11, in the presence of 5–10% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strains were closely related to members of the genus Oceanobacillus, exhibiting 99.1–99.2% similarity to O. kapialis KCTC 13177^T, 99.2–99.3% to O. picturae KCTC 3821^T, and 94.2–96% sequence similarity to other described Oceanobacillus species. SDS-PAGE of whole cell proteins preparations demonstrated that the strains exhibited high similarity to each other, but distinguished from O. kapialis KCTC 13177^T and O. picturae KCTC 3821^T (75%). DNA-DNA hybridization revealed that the similarity between the representative strain YD3-56^T and O. kapialis KCTC 13177^T was 35.3%, and the similarity between YD3-56^T and O. picturae KCTC 3821^T was 22.3%. Chemotaxonomic analysis of the strains showed menaquinone-7 was the predominant respiratory quinine. Major cellular fatty acids were anteiso-C_15:0 and anteiso-C_17:0. The polar lipid pattern for strain YD3-56^T predominantly contained phosphatidylcholine, and trace to moderate amounts of phosphatidyl ethanolamine and hydroxy-phosphatidyl ethanolamine. The diamino acid in murein was meso-diaminopimelic acid. The DNA G+C content of the strains was 39.7–40.1 mol%. On the basis of these results, the three strains should be classified as a novel species of the genus Oceanobacillus, for which the name Oceanobacillus manasiensis sp. nov. has been proposed, with the type strain as YD3-56^T (=CGMCC 1.9105^T =NBRC 105903^T).     

块菌(松露)宿主可培养内生菌群落结构与多样性研究

探究四川凉山彝族自治州块菌主产区华山松内生菌群的结构及多样性。在会东县选取4个点(新田乡、新云乡、淌塘镇、雪山乡)的块菌宿主华山松的根、茎、叶为实验材料,通过不同培养基分离样品根、茎、叶的内生细菌、真菌、放线菌,DNA分子鉴定分离菌株的种属,最终分离得到细菌46株,其中欧文氏菌属(Erwinia)5株,沙门氏菌属(Salmonell)1株,杆菌属(Bacillus)22株,葡萄球菌属(Staphylococcus)2株,假单胞菌属(Pseudomonas)2株,类芽胞杆菌属(Paenibacillus)2株,布丘氏菌属(Buttiauxella)2株,肠杆菌属(Enterobacte)3株,爱文氏菌属(Ewingella)1株,泛菌属(Rahnella)1株,拉恩氏菌属(Rahnella Izard)2株,其他属3株;真菌19株,均为子囊菌门(Ascomycota),其中青霉属(Penicillium)4株,疱霉属(Phoma)1株,子囊菌门未知菌1株,篮状菌属(Cladosporium)1株,分枝孢子菌属(Sydowia)1株,曲霉属(Aspergillus)1株,其他属10株;放线菌33株,为链霉菌属(Streptomyces)22株,短小杆菌属(Curtobacterium)2株,短杆菌属(Brevibacterium)1株,其他属8株。研究结果表明,来自不同地点、不同植株部位、不同培养基分离得到的块菌宿主华山松内生菌有差异,证实微生物在土壤、块菌、宿主植物之间有着复杂的相互作用,为块菌的人工栽培提供参考。     

Oryzicola mucosus gen. nov., sp. nov., a novel slime producing bacterium belonging to the family Phyllobacteriaceae isolated from the rhizosphere of rice plants

A novel Gram-stain negative, asporogenous, slimy, rod-shaped, non-motile bacterium ROOL2^T was isolated from the root samples collected from a rice field located in Ilsan, South Korea. Phylogenetic analysis of the 16S rRNA sequence showed 96.5% similarity to Tianweitania sediminis Z8^T followed by species of genera Mesorhizobium (96.4–95.6%), Aquabacterium (95.9–95.7%), Rhizobium (95.8%) and Ochrobactrum (95.6%). Strain ROOL2^T grew optimally at 30 °C in the presence of 1–6% (w/v) NaCl and at pH 7.5. The major respiratory quinone was ubiquinone-10 and the major cellular fatty acids were C_18:1ω7c, summed feature 4 (comprising iso-C_17:1 I and/or anteiso-C_17:1 B) and summed feature 8 (comprising C_18:1ω6c and/or C_18:1ω7c). The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylglycerol, one unidentified aminolipid and two unidentified lipids. The assembled draft genome of strain ROOL2^T had 28 contigs with N50 value of 656,326 nt, total length of 4,894,583 bp and a DNA G?+?C content of 61.5%. The average amino acid identity (AAI) values of strain ROOL2^T against the genomes of related members belonging to the same family were below 68% and the ANI and dDDH values between the strain ROOL2^T and the type strains of phylogenetically related species were 61.8–76.3% and 19.4–21.1%, respectively. Strain ROOL2^T only produces carotenoid-type pigment when grown on LB agar and slime on R2A agar. In the presence of tryptophan, strain ROOL2^T produced indole acetic acid (IAA), a phytohormone in plant growth and development. Gene clusters for indole-3-glycerol phosphatase and tryptophan synthase were found in the genome of strain ROOL2^T. The genotypic and phenotypic characteristics indicated that strain ROOL2^T represents a novel genus belonging the family Phyllobacteriaceae, for which the name Oryzicola mucosus gen. nov., sp. nov. is proposed. The type strain is ROOL2^T (KCTC 82711 ^T?=?NBRC 114717 ^T).