Aims: Thraustochytrids have been shown to be excellent lipid producers due to their ability to accumulate over 50% lipid (g/g biomass) containing up to 50% docosahexaenoic acid (DHA). However, efficient and cost-effective cell recovery of lipid-rich biomass has become a significant challenge at the industrial scale. In this study, we attempted to enhance the harvesting efficiency (HE) and the DHA content of Aurantiochytrium sp. through co-cultivation with a γ-linolenic acid (GLA)-producing oleaginous filamentous fungus, Cunninghamella bainieri 2A1. Methodology and results: A 72 h old C. bainieri 2A1 culture in the form of loose mycelia or pellets of various sizes was added into 72 h old Aurantiochytrium sp. cultures and further incubated for 48 h. The HE of Aurantiochytrium sp. was then determined by comparing the remaining OD values of the supernatant with and without minimal centrifugation at 4000× g. Results showed that 63.23% of HE was achieved without centrifugation from co-cultivation with dispersed mycelia. Higher HE between 96.71-99.55% was achieved when centrifugation was implemented, with the highest value resulting from co-cultivation with dispersed mycelia. These are higher than HE of centrifuged control cultures (80%) consisting of Aurantiochytrium sp. monocultures, suggesting that co-cultivation with C. bainieri 2A1 facilitates the recovery of Aurantiochytrium sp. cells. Moreover, the co-cultivation also resulted in a 28% increase in DHA compared to non-optimized cultures. Conclusion, significance and impact of study This study provides the first evidence of enhancement in harvesting and DHA content of oleaginous thraustochytrids that could be achieved through co-cultivation with oleaginous fungi.
Heterotrophic Processes ; Cunninghamella ; Eukaryota

Aspergillosis ; Humans ; Mucor ; Mucormycosis/drug therapy*

We report a case of mucormycosis induced by Cunninghamella spp. infection in a ten-year-old girl with acute lymphoblastic leukemia, who developed fever and respiratory symptoms after chemotherapy and was diagnosed with invasive fungal disease. Peripheral blood DNA sequences were analyzed using metagenomic next-generation sequencing (mNGS), and by comparison with the Pathogens Metagenomics Database (PMDB), we identified Cunninghamella spp. with sequence number 514 as the pathogen. The patient was treated with amphotericin B combined with posaconazole and showed a favorable response. We searched Pubmed, Embase, CNKI, and Wanfang database for reports of cases of Cunninghamella spp. infection in children and retrieved 22 reported cases (including 12 males) with a median age of 13.5 (3-18) years. In these 22 cases, hematological malignancy was the most common underlying condition (19/22), and most of patients experienced an acute onset and rapid progression with respiratory symptoms (14/20) and fever (16/20) as the most common symptoms. CT imaging often showed unilateral lesions with varying imaging findings, including pulmonary nodules or masses, infiltrative changes, and pleural effusion. Definite diagnoses were established in 18 of the cases, and 4 had probable diagnoses; the lungs and skin were the most frequent organs compromised by the infection. A definite diagnosis of Cunninghamella spp. infection still relied on histopathological examination and fungal culture, but the molecular techniques including PCR and mNGS had shown potentials in the diagnosis. Almost all the cases received antifungal treatment after diagnosis (21/22), and 13 patients also underwent surgeries. Death occurred in 9 (42%) of the cases at a median of 19 (4-54) days after onset of the signs or symptoms. The patients receiving antifungal therapy combined with surgery had a high survival rate (9/13, 69%) than those with antifungal therapy alone (3/8, 37%). Invasive fungal disease is a common complication in immunoco-mpromised patients, but Cunninghamella spp. infection is rare and has a high mortality rate. In cases highly suspected of this disease, active diagnosis and early treatment are critical to improve the survival outcomes of the patients.
Adolescent ; Amphotericin B/therapeutic use* ; Antifungal Agents/therapeutic use* ; Child ; Cunninghamella ; Female ; Humans ; Male ; Mucormycosis/etiology*

L-asparaginase hydrolyzes L-asparagine to produce L-aspartic acid and ammonia. It is widely distributed in microorganisms, plants and serum of some rodents, and has important applications in the pharmaceutical and food industries. However, the poor thermal stability, low catalytic efficiency and low yield hampered the further application of L-asparaginase. In this paper, rational design and 5' untranslated region (5'UTR) design strategies were used to increase the specific enzyme activity and protein expression of L-asparaginase derived from Rhizomucor miehei (RmAsnase). The results showed that among the six mutants constructed through homology modeling combined with sequence alignment, the specific enzyme activity of the mutant A344E was 1.5 times higher than the wild type. Subsequently, a food-safe strain Bacillus subtilis 168/pMA5-A344E was constructed, and the UTR strategy was used for the construction of recombinant strain B. subtilis 168/pMA5 UTR-A344E. The enzyme activity of B. subtilis 168/pMA5 UTR-A344E was 7.2 times higher than that of B. subtilis 168/pMA5-A344E. The recombinant strain B. subtilis 168/pMA5 UTR-A344E was scaled up in 5 L fermenter, and the final yield of L-asparaginase was 489.1 U/mL, showing great potential for industrial application.
Asparaginase/genetics* ; Bacillus subtilis/genetics* ; Industrial Microbiology ; Protein Engineering ; Rhizomucor/enzymology* ; Sequence Alignment

Blakeslea trispora is a natural source of carotenoids, including β-carotene and lycopene, which have industrial applications. Therefore, classical selective breeding techniques have been applied to generate strains with increased productivity, and microencapsulated β-carotene preparation has been used in food industry (Li et al., 2019). In B. trispora, lycopene is synthesized via the mevalonate pathway (Venkateshwaran et al., 2015). Lycopene cyclase, which is one of the key enzymes in this pathway, is a bifunctional enzyme that can catalyze the cyclization of lycopene to produce β-carotene and exhibit phytoene synthase activity (He et al., 2017).
Citric Acid Cycle ; Fermentation ; Gas Chromatography-Mass Spectrometry/methods* ; Lycopene/metabolism* ; Mucorales/metabolism* ; Nicotine/pharmacology* ; beta Carotene/biosynthesis*

Three fungal isolates designated as CNUFC-YR329-1, CNUFC-PTS103-1, and CNUFC-PTS2-1 were discovered during a survey of fungal diversity of the order Mortierellales from freshwater and pine tree rhizosphere soil samples in Korea. The strains were analyzed morphologically and phylogenetically based on the internal transcribed spacer (ITS) and large subunit (LSU) of ribosomal DNA gene sequences. Based on their morphology and phylogeny, the three isolates were identified as Mortierella elongata, M. horticola, and M. humilis, respectively. To the best of our knowledge, M. elongata, M. horticola, and M. humilis, belonging to an undiscovered taxon, have not been previously described in Korea.
Classification ; DNA, Ribosomal ; Fresh Water ; Korea ; Mortierella ; Phylogeny ; Pinus ; Rhizosphere ; Soil

Adult ; Alternaria ; immunology ; Alveolitis, Extrinsic Allergic ; immunology ; Animals ; Antibodies ; immunology ; Antibodies, Bacterial ; immunology ; Antibodies, Fungal ; immunology ; Antigens ; immunology ; Antigens, Bacterial ; immunology ; Antigens, Fungal ; immunology ; Aspergillus fumigatus ; immunology ; Asymptomatic Diseases ; Candida albicans ; immunology ; Cladosporium ; immunology ; Columbidae ; immunology ; Female ; Healthy Volunteers ; Humans ; Immunoglobulin G ; immunology ; Male ; Melopsittacus ; immunology ; Middle Aged ; Mucor ; immunology ; Nocardia ; immunology ; Parrots ; immunology ; Penicillium chrysogenum ; immunology ; Stachybotrys ; immunology ; Thermoactinomyces ; immunology

Mucormycosis is an extremely rare but potentially life-threatening fungal infection. Gastrointestinal (GI) mucormycosis is very rare and occurs primarily in highly malnourished patients, especially in infants and children. A 55-year-old man with end-stage renal disease due to diabetic nephropathy, who had undergone deceased donor kidney transplantation 2 years prior, complained of abdominal pain and distension with a 3-day duration. Computed tomography revealed diffuse gastric wall thickening, and a huge amount of grey colored necrotic debris surrounded by erythematous erosive mucosa was observed at the antrum to upper body by GI endoscopy. The microscopic examination obtained from a GI endoscopic specimen demonstrated peptic detritus with numerous non-septate mucor hyphae in the mucosa and submucosa. Mucormycosis was diagnosed based on the clinical findings and morphological features. A total gastrectomy was performed and an antifungal agent was administered. A microscopic examination of the surgical specimen demonstrated invasive mucormycosis with numerous fungal hyphae with invasion into the mucosa to subserosa. The patient and graft were treated successfully by total gastrectomy and antifungal therapy.
Abdominal Pain ; Child ; Diabetic Nephropathies ; Endoscopy ; Gastrectomy ; Humans ; Hyphae ; Infant ; Kidney Failure, Chronic ; Kidney Transplantation ; Kidney* ; Middle Aged ; Mucor ; Mucormycosis* ; Mucous Membrane ; Stomach ; Tissue Donors ; Transplant Recipients* ; Transplants

While surveying undiscovered fungal taxa in Korea, three rare zygomycetous fungal strains, CNUFC-PTF2-1, CNUFC-TF3-1, and CNUFC-ESAF3-1, were isolated from soil, leaf, and freshwater samples, respectively. The strains were analyzed morphologically as well as phylogenetically based on the internal transcribed spacer region and 28S rDNA sequences. Sequence analysis of the two loci revealed that the isolates, CNUFC-PTF2-1, CNUFC-TF3-1, and CNUFC-ESAF3-1, were identified as Backusella circina, Circinella muscae, and Mucor ramosissimus, respectively. These species have not yet been previously described in Korea.
Classification ; DNA, Ribosomal ; Fresh Water ; Fungi* ; Korea* ; Mucor* ; Sequence Analysis ; Soil

The order Mucorales, the largest in number of species within the Mucoromycotina, comprises typically fast-growing saprotrophic fungi. During a study of the fungal diversity of undiscovered taxa in Korea, two novel mucoralean strains, CNUFC-GWD3-9 and CNUFC-EGF1-4, were isolated from specific habitats including freshwater and fecal samples, respectively. On the basis of their morphological characteristics and sequence analyses of internal transcribed spacer and large subunit ribosomal DNA, the CNUFC-GWD3-9 and CNUFC-EGF1-4 isolates were confirmed to be Gilbertella persicaria and Pilobolus crystallinus, respectively. It is ecologically, pathologically, and mycologically significant to find such rare zygomycetous fungi in such specific habitats.
DNA, Ribosomal ; Ecosystem* ; Fresh Water ; Fungi ; Korea ; Mucorales ; Phylogeny ; Sequence Analysis