Helicovermis profundi gen. nov., sp. nov., a novel mesophilic, asporogenous bacterium within the Clostridia isolated from a deep-sea hydrothermal vent chimney.

A novel mesophilic bacterial strain, designated S502T, was isolated from a deep-sea hydrothermal vent at Suiyo Seamount, Japan. Cells were Gram-positive, asporogenous, motile, and curved rods, measuring 1.6-5.6 µm in length. The strain was an obligate anaerobe that grew fermentatively on complex substrates such as yeast extract and Bacto peptone. Elemental sulfur stimulated the growth of the strain, and was reduced to hydrogen sulfide. The strain grew within a temperature range of 10-23 °C (optimum at 20 °C), pH range of 4.8-8.3 (optimum at 7.4), and a NaCl concentration range of 1.0-4.0% (w/v) (optimum at 3.0%, w/v). Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolate was a member of the class Clostridia, with Fusibacter paucivorans strain SEBR 4211T (91.1% sequence identity) being its closest relative. The total size of the genome of the strain was 3.12 Mbp, and a G + C content was 28.2 mol%. The highest values for average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) value of strain S502T with relatives were 67.5% (with Marinisporobacter balticus strain 59.4MT), 51.5% (with M. balticus strain 59.4MT), and 40.9% (with Alkaliphilus serpentinus strain LacTT), respectively. Based on a combination of phylogenetic, genomic, and phenotypic characteristics, we propose strain S502T to represent a novel genus and species, Helicovermis profundi gen. nov., sp. nov., with the type strain S502T (= DSM 112048T = JCM 39167T).

Haliovirga abyssi gen. nov., sp. nov., a mesophilic fermentative bacterium isolated from the Iheya North hydrothermal field, and proposal of Haliovirgaceae fam. nov.

A novel mesophilic, obligately anaerobic, facultatively sulphur-reducing bacterium, designated strain IC12T, was isolated from a deep-sea hydrothermal field in the Mid-Okinawa Trough, Japan. The cells were Gram-negative, motile, short rods with a single polar flagellum. The ranges and optima of the growth temperature, NaCl concentration and pH of strain IC12T were 15-40 °C (optimum, 30-35 °C), 10-60 g l-1 (optimum, 20-30 g l-1) and pH 4.9-6.7 (optimum, pH 5.8), respectively. Yeast extract was utilized as a sole carbon and energy source for fermentative growth. Major fatty acids of strain IC12T were C14 : 0, C16 : 0 and C16 : 1 ω7. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain IC12T was affiliated to the phylum Fusobacteriota and was most closely related to Ilyobacter insuetus VenChi2T (86.5 % sequence similarity). Strain IC12T contained a chromosome of 2.43 Mbp and a large plasmid of 0.30 Mbp. The G+C content of the genomic DNA was 26.4 mol%. The maximum values for average nucleotide identity and in silico DNA-DNA hybridization between strain IC12T and related strains of the phylum Fusobacteriota were 71.4 and 26.4 %, respectively. Phylogenomic, physiological and chemotaxonomic analyses indicate that strain IC12T represents a novel genus and species within the phylum Fusobacteriota, for which the name Haliovirga abyssi gen. nov., sp. nov. is proposed, with strain IC12T (= DSM 112164T=JCM 39166T) as the type strain. We also propose the family Haliovirgaceae fam. nov. to accommodate this novel genus.

Pyrofollis japonicus gen. nov. sp. nov., a novel member of the family Pyrodictiaceae isolated from the Iheya North hydrothermal field.

A novel hyperthermophilic, heterotrophic archaeon, strain YC29T, was isolated from a deep-sea hydrothermal vent in the Mid-Okinawa Trough, Japan. Cells of strain YC29T were non-motile, irregular cocci with diameters of 1.2-3.0 µm. The strain was an obligatory fermentative anaerobe capable of growth on complex proteinaceous substrates. Growth was observed between 85 and 100 °C (optimum 90-95 °C), pH 4.9-6.4 (optimum 5.1), and in the presence of 1.4-4.0% (w/v) NaCl (optimum 3.0%). Inorganic carbon was required as a carbon source. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolate was a member of the family Pyrodictiaceae. The genome size was 2.02 Mbp with a G+C content of 49.4%. The maximum values for average nucleotide identity (ANI), average amino acid identity (AAI), and in silico DNA-DNA hybridization (dDDH) value of strain YC29T with relatives were 67.9% (with Pyrodictium abyssi strain AV2T), 61.1% (with Pyrodictium occultum strain PL-19T), and 33.8% (with Pyrolobus fumarii strain 1AT), respectively. Based on the phylogenetic, genomic, and phenotypic characteristics, we propose that strain YC29T represents a novel genus and species, Pyrofollis japonicus gen. nov., sp. (type strain YC29T = DSM 113394T = JCM 39171T).

Transcriptome analysis of Aurantiochytrium limacinum under low salt conditions.

Aurantiochytrium limacinum can accumulate high amounts of omega-3 polyunsaturated fatty acids, especially docosahexaenoic acid (DHA). Although salinity affects the DHA content, its impact on the metabolic pathway responsible for DHA production in A. limacinum is not completely understood. To address this issue, we investigated the transcriptional profile of A. limacinum under hypoosmotic stress. We first cultured A. limacinum under typical and low salinity for RNA sequencing, respectively. Transcriptome analyses revealed that 933 genes exhibited significant changes in expression under hypoosmotic conditions, of which 81.4% were downregulated. Strikingly, A. limacinum downregulated genes related to polyketide synthesis and fatty acid synthase pathways, while upregulating ß-oxidation-related genes. In accordance with this, DHA production significantly decreased under hypoosmotic conditions, while antioxidant-related genes were significantly upregulated. Considering that ß-oxidation of fatty acids generates energy and reactive oxygen species (ROS), our results suggest that A. limacinum utilizes fatty acids for energy to survive under hypoosmotic conditions and detoxifies ROS using antioxidant systems.

Transcriptional responses of Aurantiochytrium limacinum under light conditions.

AIMS: Astaxanthin-producing protist Aurantiochytrium limacinum can accumulate higher amounts of astaxanthin under light conditions; however, little is known about the impact of light exposure on its metabolism. Here, we investigated the transcriptional profile of A. limacinum under light conditions. METHODS AND RESULTS: Transcriptomic analyses revealed that 962 genes of A. limacinum showed a significant change in expression under light conditions, most of which (94.5%) were downregulated. Furthermore, gene ontology enrichment analysis indicated that A. limacinum mainly downregulated genes associated with cell motility, proliferation and gene expression processes, whose activities depend on ATP as an energy source. Additionally, the quantification of carotenoid and its transcripts suggested that ß-carotene and astaxanthin biosynthesis pathways were rate-limiting and tightly regulated steps, respectively. In comparison, these processes were enhanced under light conditions. CONCLUSIONS: Considering that astaxanthin accumulation was highly correlated with reactive oxygen species (ROS) levels in microalgae, our results suggest that A. limacinum reduces ATP consumption to decrease the occurrence of ROS in mitochondria while accumulating astaxanthin to prevent ROS damage. SIGNIFICANCE AND IMPACT OF STUDY: This study provides novel insights into the impact of light exposure on A. limacinum metabolism, thereby facilitating a complete understanding of this protist for efficient astaxanthin production.

Desulfomarina profundi gen. nov., sp. nov., a novel mesophilic, hydrogen-oxidizing, sulphate-reducing chemolithoautotroph isolated from a deep-sea hydrothermal vent chimney.

A novel mesophilic, strictly anaerobic, chemolithoautotrophic sulphate-reducing bacterium, designated strain KT2T, was isolated from a deep-sea hydrothermal vent chimney at the Suiyo Seamount in the Izu-Bonin Arc. Strain KT2T grew at 25-40 °C (optimum 35 °C) and pH 5.5-7.0 (optimum 6.6) in the presence of 25-45 g l-1 NaCl (optimum 30 g l-1). Growth occurred with molecular hydrogen as the electron donor and sulphate, thiosulphate, and sulphite as the electron acceptors. The isolate utilized CO2 as the sole carbon source for chemolithoautotrophic growth on H2. Glycerol, succinate, fumarate, malate, glutamate, or casamino acids could serve as an alternative electron donor in the presence of CO2. Malate, citrate, glutamate, and casamino acids were used as fermentative substrates for weak growth. The G+C content of genomic DNA was 46.1 %. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain KT2T is a member of the family Desulfobulbaceae, showing a sequence similarity of 94.3 % with Desulforhopalus singaporensis. Phylogenomic analysis based on concatenated 156 single-copy marker genes confirmed the same topology as the 16S rRNA gene phylogeny. The ANI and AAI values between strain KT2T and related genera of the family Desulfobulbaceae were 65.6-68.6 % and 53.1-62.9 %. Based on the genomic, molecular, and physiological characteristics, strain KT2T represents a novel genus and species within the family Desulfobulbaceae, for which the name Desulfomarina profundi gen. nov., sp. nov. is proposed, with KT2T (=JCM 34118T = DSM 111364T) as the type strain.

Identification and characterization of d-arabinose reductase and d-arabinose transporters from Pichia stipitis.

d-xylose and l-arabinose are the major constituents of plant lignocelluloses, and the related fungal metabolic pathways have been extensively examined. Although Pichia stipitis CBS 6054 grows using d-arabinose as the sole carbon source, the hypothetical pathway has not yet been clarified at the molecular level. We herein purified NAD(P)H-dependent d-arabinose reductase from cells grown on d-arabinose, and found that the enzyme was identical to the known d-xylose reductase (XR). The enzyme activity of XR with d-arabinose was previously reported to be only 1% that with d-xylose. The kcat/Km value with d-arabinose (1.27 min-1 mM-1), which was determined using the recombinant enzyme, was 13.6- and 10.5-fold lower than those with l-arabinose and d-xylose, respectively. Among the 34 putative sugar transporters from P. stipitis, only seven genes exhibited uptake ability not only for d-arabinose, but also for d-glucose and other pentose sugars including d-xylose and l-arabinose in Saccharomyces cerevisiae.

Production of ß-xylosidase from Trichoderma asperellum KIF125 and its application in efficient hydrolysis of pretreated rice straw with fungal cellulase.

On-site cellulase and hemicellulase production is a promising way to reduce enzyme cost in the commercialization of the lignocellulose-to-ethanol process. A hemicellulase-producing fungal strain suitable for on-site enzyme production was selected from cultures prepared using wet disc-milling rice straw (WDM-RS) and identified as Trichoderma asperellum KIF125. KIF125 hemicellulase showed uniquely high abundance of ß-xylosidase in the xylanolytic enzyme system compared to other fungal hemicellulase preparations. Supplementation of Talaromyces cellulolyticus cellulase with KIF125 hemicellulase was more effective than that with the hemicellulases from other fungal sources in reducing the total enzyme loading for the improvement of xylose yield in the hydrolysis of ball-milling RS, due to its high ß-xylosidase dominance. ß-Xylosidase in KIF125 hemicellulase was purified and classified as a glycosyl hydrolase family 3 enzyme with relatively high specificity for xylobiose. The production of KIF125 ß-xylosidase in the fermentor was estimated as 118 U/g-WDM-RS (2350 U/L culture) at 48 h. These results demonstrate that KIF125 is promising as a practical hemicellulase source to combine with on-site cellulase production using T. cellulolyticus.

Breeding of a xylose-fermenting hybrid strain by mating genetically engineered haploid strains derived from industrial Saccharomyces cerevisiae.

The industrial Saccharomyces cerevisiae IR-2 is a promising host strain to genetically engineer xylose-utilizing yeasts for ethanol fermentation from lignocellulosic hydrolysates. Two IR-2-based haploid strains were selected based upon the rate of xylulose fermentation, and hybrids were obtained by mating recombinant haploid strains harboring heterogeneous xylose dehydrogenase (XDH) (wild-type NAD(+)-dependent XDH or engineered NADP(+)-dependent XDH, ARSdR), xylose reductase (XR) and xylulose kinase (XK) genes. ARSdR in the hybrids selected for growth rates on yeast extract-peptone-dextrose (YPD) agar and YP-xylose agar plates typically had a higher activity than NAD(+)-dependent XDH. Furthermore, the xylose-fermenting performance of the hybrid strain SE12 with the same level of heterogeneous XDH activity was similar to that of a recombinant strain of IR-2 harboring a single set of genes, XR/ARSdR/XK. These results suggest not only that the recombinant haploid strains retain the appropriate genetic background of IR-2 for ethanol production from xylose but also that ARSdR is preferable for xylose fermentation.

Bench-scale bioethanol production from eucalyptus by high solid saccharification and glucose/xylose fermentation method.

In the bioethanol production process, high solid saccharification and glucose/xylose co-fermentation are important technologies for obtaining increased ethanol concentrations; however, bench-scale studies using combinations of these methods are limited. In this study, we hydrolyzed high solid concentration of milled eucalyptus using commercial enzymes and obtained 138.4 g/L total monomeric sugar concentration. These sugars were fermented to 53.5 g/L of ethanol by a xylose-utilizing recombinant Saccharomyces cerevisiae strain, MA-R4. These experiments were performed in bench scale (using 50 L scale solid mixer and 70 L scale fermenter). The results obtained in this study were comparable to our previous results in laboratory scale, indicating that we successfully achieved an efficient high solid saccharification and glucose/xylose co-fermentation system in bench scale.

High-coverage gene expression profiling analysis of the cellulase-producing fungus Acremonium cellulolyticus cultured using different carbon sources.

The gene expression of a cellulase-producing fungus, Acremonium cellulolyticus, was investigated after culturing with three different carbon sources: glycerol, lactose, and Solka-Floc powdered cellulose (SF). High-coverage gene expression profiling (HiCEP) analysis, a method requiring no prior sequence knowledge, was used to screen genes upregulated at the early stage of cellulase production. SF was used as a strong inducer of cellulase production, lactose was used as an inducer of the expression of cellulase genes at the early stage of the culture, and glycerol was used as a negative control. Approximately 15,000 transcript-derived fragments (TDFs) were detected in each sample prepared from the culture grown for 16 h. Based on the expression profiles of the cultured cells, 36 fragments upregulated in both the SF and lactose cultures were selected and sequenced. The deduced gene products of 31 TDFs were likely related to biomass degradation, sugar metabolism, transcriptional regulation, protein modification and metabolism, cell wall recycling, fatty acid and polyketide biosynthesis, and other functions. Quantitative real-time reverse-transcriptase polymerase chain reaction analysis verified that almost all of the transcripts obtained by HiCEP analysis were upregulated in the SF and lactose cultures grown for 18 h. Some of the TDFs in the SF culture were further upregulated over the course of 72 h. The gene products from these TDFs would provide insight into improving the cellulase productivity of A. cellulolyticus.

A Simple and Effective Method for Solid Medium Cultivation of Strictly Hydrogen- and Sulfur-oxidizing Chemolithoautotrophs Predominant in Deep-|sea Hydrothermal Fields.

Strictly hydrogen- and sulfur-oxidizing chemolithoautotrophic bacteria, particularly members of the phyla Campylobacterota and Aquificota, have a cosmopolitan distribution in deep-sea hydrothermal fields. The successful cultivation of these microorganisms in liquid media has provided insights into their physiological, evolutionary, and ecological characteristics. Notably, recent population genetic studies on Sulfurimonas (Campylobacterota) and Persephonella (Aquificota) revealed geographic separation in their populations. Advances in this field of research are largely dependent on the availability of pure cultures, which demand labor-intensive liquid cultivation procedures, such as dilution-to-extinction, given the longstanding assumption that many strictly or facultatively anaerobic chemolithoautotrophs cannot easily form colonies on solid media. We herein describe a simple and cost-effective approach for cultivating these chemolithoautotrophs on solid media. The results obtained suggest that not only the choice of gelling agent, but also the gas phase composition significantly affect the colony-forming ratio of diverse laboratory strains. The use of gellan gum as a gelling agent combined with high concentrations of H2 and CO2 in a pouch bag promoted the formation of colonies. This contrasted with the absence of colony formation on an agar-solidified medium, in which thiosulfate served as an electron donor, nitrate as an electron acceptor, and bicarbonate as a carbon source, placed in anaerobic jars under an N2 atmosphere. Our method efficiently isolated chemolithoautotrophs from a deep-sea vent sample, underscoring its potential value in research requiring pure cultures of hydrogen- and sulfur-oxidizing chemolithoautotrophs.

Improvement of Astaxanthin Production in Aurantiochytrium limacinum by Overexpression of the Beta-Carotene Hydroxylase Gene.

Aurantiochytrium limacinum is a heterotrophic eukaryotic microorganism that can accumulate high levels of commercial products such as astaxanthin and docosahexaenoic acid. Due to its rapid growth and relatively simple extraction method, A. limacinum is considered a promising astaxanthin resource to replace the conventional microalgal production. However, the astaxanthin biosynthetic process in A. limacinum remains incompletely understood, especially in those catalysed by ß-carotene hydroxylase (CrtZ) and ketolase. In this study, we overexpressed a crtZ candidate gene to increase astaxanthin production and expand our understanding of the conversion from beta-carotene to astaxanthin. The resultant transformant AlcrtZ#10 cultivated for 5 days showed a significant increase in astaxanthin production per culture (2.8-fold) and per cell (4.5-fold) compared with that of the wild-type strain. Strikingly, longer light exposure increased astaxanthin production and decreased the beta-carotene content in the wild-type strain, suggesting that light exposure duration is important for astaxanthin production in A. limacinum. Among several predicted intermediates, furthermore, the cantaxanthin produced from ß-carotene by ketolase activity were enhanced in the transformant AlcrtZ#10. Although the further investigation is needed, this result suggested that the main route of astaxanthin was via cantaxanthin. Thus, our findings will be valuable not only for its application, but also for understanding the astaxanthin biosynthetic process in A. limacinum.

Isolation of uracil auxotrophs of the fungus Acremonium cellulolyticus and the development of a transformation system with the pyrF gene.

Acremonium cellulolyticus CF-2612 is a cellulase hyper-producing mutant that originated from A. cellulolyticus Y-94. In this study, we isolated a uracil auxotroph (strain CFP3) derived from CF-2612, and cloned a wild-type pyrF gene encoding orotate phosphoribosyl transferase (OPRTase) from Y-94. OPRTase activity was not detected in strain CFP3, which had one nucleotide substitution in its pyrF gene. The wild-type pyrF gene restored the defective growth of CFP3 on uracil-free medium, and PCR and Southern analyses revealed that wild-type pyrF was integrated into the genome. These results indicate that our transformation system for A. cellulolyticus with the pyrFgene as a selection marker was successful.

Physiological and comparative proteomic characterization of Desulfolithobacter dissulfuricans gen. nov., sp. nov., a novel mesophilic, sulfur-disproportionating chemolithoautotroph from a deep-sea hydrothermal vent.

In deep-sea hydrothermal environments, inorganic sulfur compounds are important energy substrates for sulfur-oxidizing, -reducing, and -disproportionating microorganisms. Among these, sulfur-disproportionating bacteria have been poorly understood in terms of ecophysiology and phylogenetic diversity. Here, we isolated and characterized a novel mesophilic, strictly chemolithoautotrophic, diazotrophic sulfur-disproportionating bacterium, designated strain GF1T, from a deep-sea hydrothermal vent chimney at the Suiyo Seamount in the Izu-Bonin Arc, Japan. Strain GF1T disproportionated elemental sulfur, thiosulfate, and tetrathionate in the presence of ferrihydrite. The isolate also grew by respiratory hydrogen oxidation coupled to sulfate reduction. Phylogenetic and physiological analyses support that strain GF1T represents the type strain of a new genus and species in the family Desulfobulbaceae, for which the name Desulfolithobacter dissulfuricans gen. nov. sp. nov. is proposed. Proteomic analysis revealed that proteins related to tetrathionate reductase were specifically and abundantly produced when grown via thiosulfate disproportionation. In addition, several proteins possibly involved in thiosulfate disproportionation, including those encoded by the YTD gene cluster, were also found. The overall findings pointed to a possible diversity of sulfur-disproportionating bacteria in hydrothermal systems and provided a refined picture of microbial sulfur disproportionation.

Ethanol production from xylo-oligosaccharides by xylose-fermenting Saccharomyces cerevisiae expressing ß-xylosidase.

Construction of xylose- and xylo-oligosaccharide-fermenting Saccharomyces cerevisiae strains is important, because hydrolysates derived from lignocellulosic biomass contain significant amounts of these sugars. We have obtained recombinant S. cerevisiae strain MA-D4 (D-XKXDHXR), expressing xylose reductase, xylitol dehydrogenase and xylulokinase. In the present study, we generated recombinant strain D-XSD/XKXDHXR by transforming MA-D4 with a ß-xylosidase gene cloned from the filamentous fungus Trichoderma reesei. The intracellular ß-xylosidase-specific activity of D-XSD/XKXDHXR was high, while that of the control strain was under the limit of detection. D-XSD/XKXDHXR produced ethanol, and xylose accumulated in the culture supernatant under fermentation in a medium containing xylo-oligosaccharides as sole carbon source. ß-Xylosidase-specific activity in D-XSD/XKXDHXR declined due to xylose both in vivo and in vitro. D-XSD/XKXDHXR converted xylo-oligosaccharides in an enzymatic hydrolysate of eucalyptus to ethanol. These results indicate that D-XSD/XKXDHXR efficiently converted xylo-oligosaccharides to xylose and subsequently to ethanol.

Enhanced Production of Astaxanthin without Decrease of DHA Content in Aurantiochytrium limacinum by Overexpressing Multifunctional Carotenoid Synthase Gene.

Aurantiochytrium limacinum produces both docosahexaenoic acid (DHA) and astaxanthin, respectively. Organisms that produce these industrially important materials more efficiently than microalgae are currently needed. In this study, we overexpressed a putative homolog of CarS, which is involved in synthesizing the astaxanthin precursor, ß-carotene, in A. limacinum to increase carotenoid synthesis with the goal of obtaining strains that produce large amounts of both DHA and carotenoids. AlCarS transformants #1 and #18 produced significantly increased amounts of astaxanthin as assessed according to culture (up to 5.8-fold) and optical density (up to 9.3-fold). The improved astaxanthin production of these strains did not affect their DHA productivity. Additionally, their CarS expression levels were higher than those of the wild-type strain, suggesting that CarS overexpression enhanced ß-carotene production, which in turn improved astaxanthin productivity. Although cell yields were slightly decreased, these features will be valuable in health food, medical care, and animal feed fields.

Enhanced Lutein Production in Chlamydomonas reinhardtii by Overexpression of the Lycopene Epsilon Cyclase Gene.

Chlamydomonas reinhardtii is a well-established microalgal model species with a shorter doubling time, which is a promising natural source for the efficient production of high-value carotenoids. In the microalgal carotenoid biosynthetic pathway, lycopene is converted either into ß-carotene by lycopene ß-cyclase or into α-carotene by lycopene ε-cyclase (LCYE) and lycopene ß-cyclase. In this study, we overexpressed the LCYE gene in C. reinhardtii to estimate its effect on lycopene metabolism and lutein production. Chlamydomonas transformants (CrLCYE#L1, #L5, and #L6) produced significantly increased amounts of lutein per culture (up to 2.6-fold) without a decrease in cell yields. Likewise, the expression levels of LCYE gene in transformants showed a significant increase compared with that of the wild-type strain. These results suggest that LCYE overexpression enhances the conversion of lycopene to α-carotene, which in turn improves lutein productivity. Interestingly, their ß-carotene productivity appeared to increase slightly rather than decrease. Considering that the inhibition of the lycopene cyclization steps often induces higher expression in genes upstream of metabolic branches, this result implies that the redirection from ß-carotene to α-carotene by LCYE overexpression might also enhance upstream gene expression, thereby leading to auxiliary ß-carotene production.

Cellulase hyperproducing mutants derived from the fungus Trichoderma reesei QM9414 produced large amounts of cellulase at the enzymatic and transcriptional levels.

Cellulase hyperproducing mutants derived from the fungus Trichoderma reesei QM9414 were analyzed. They exhibited higher filter-paper degrading activity and a lower growth rate than the wild-type QM9414 strain. Transcription of the cellobiohydrolase I and endoglucanase I genes in the mutants was also greater than that of QM9414, suggesting that cellulase hyperproduction by these mutants was regulated at the transcriptional level.

Draft Genome Sequence of the Astaxanthin-Producing Microalga Haematococcus lacustris Strain NIES-144.

Haematococcus lacustris is an industrially important eukaryotic microalga that is thought to be a great source of natural astaxanthin with strong antioxidant activity. Here, we report the draft assembly and annotation results of the genome of H. lacustris NIES-144. These data will expand our knowledge of the molecular biological features of this microalga.