Co-cultivation System Research Articles

Municipal wastewater treatment using an innovative two-stage sequential microalgal co-cultivation system with different hydraulic retention time: A sustainable approach to circular economy

The present study proposes a sustainable circular bioeconomy approach for municipal wastewater (MWW) treatment, employing a sub-pilot two-stage sequential microalgal co-cultivation system (TSSCS), and evaluates the impact of hydraulic retention time (HRT) on MWW treatment efficiency, as well as biomass and biomolecule productivity. In the first stage of TSSCS, 2 ratios of Tetraselmis indica and one ratio of Picochlorum sp. (2TS:1PC) were used for the treatment of 75% raw MWW + 25% ASN-III, while in the second stage, 2PC:1TS was employed for the treatment of 50% 2TS:1PC effluent+ 50% ASN-III. At the end of the first and second stages of TSSCS, nutrient removal efficiencies were as follows: total nitrate (TN) was <80% and 90% on HRT-10 and HRT-12; total phosphate (TP) was <85% and 95% on HRT-16, and chemical oxygen demand (COD) was <75% and <85% on HRT-14 and HRT-10, respectively. In the TSSCS, 2TS:1PC (S1) and 2PC:1TS (S2) showed maximum biomass productivity of 2.65 and 2.78g/L on /L on HRT-14 and HRT-12, respectively. Additionally, biomass of 2TS:1PC (S1) and 2PC:1TS (S2) contains lipid content (38.67 and 40.67%), β-carotene (4.09 and 3.00mg/g), and astaxanthin (0.69 and 0.31mg/g), respectively.

Co-existence of two antibiotic-producing marine bacteria: Pseudoalteromonas piscicida reduce gene expression and production of the antibacterial compound, tropodithietic acid, in Phaeobacter sp.

Many bacteria co-exist and produce antibiotics, yet we know little about how they cope and occupy the same niche. The purpose of the present study was to determine if and how two potent antibiotic-producing marine bacteria influence the secondary metabolome of each other. We established an agar- and broth-based system allowing co-existence of a Phaeobacter species and Pseudoalteromonas piscicida that, respectively, produce tropodithietic acid (TDA) and bromoalterochromides (BACs). Co-culturing of Phaeobacter sp. strain A36a-5a on Marine Agar with P. piscicida strain B39bio caused a reduction of TDA production in the Phaeobacter colony. We constructed a transcriptional gene reporter fusion in the tdaC gene in the TDA biosynthetic pathway in Phaeobacter and demonstrated that the reduction of TDA by P. piscicida was due to the suppression of the TDA biosynthesis. A stable liquid co-cultivation system was developed, and the expression of tdaC in Phaeobacter was reduced eightfold lower (per cell) in the co-culture compared to the monoculture. Mass spectrometry imaging of co-cultured colonies revealed a reduction of TDA and indicated that BACs diffused into the Phaeobacter colony. BACs were purified from Pseudoalteromonas; however, when added as pure compounds or a mixture they did not influence TDA production. In co-culture, the metabolome was dominated by Pseudoalteromonas features indicating that production of other Phaeobacter compounds besides TDA was reduced. In conclusion, co-existence of two antibiotic-producing bacteria may be allowed by one causing reduction in the antagonistic potential of the other. The reduction (here of TDA) was not caused by degradation but by a yet uncharacterized mechanism allowing Pseudoalteromonas to reduce expression of the TDA biosynthetic pathway.IMPORTANCEThe drug potential of antimicrobial secondary metabolites has been the main driver of research into these compounds. However, in recent years, their natural role in microbial systems and microbiomes has become important to determine the assembly and development of microbiomes. Herein, we demonstrate that two potent antibiotic-producing bacteria can co-exist, and one mechanism allowing the co-existence is the specific reduction of antibiotic production in one bacterium by the other. Understanding the molecular mechanisms in complex interactions provides insights for applied uses, such as when developing TDA-producing bacteria for use as biocontrol in aquaculture.

Auxin-Producing Bacteria Used as Microbial Biostimulants Improve the Growth of Tomato (Solanum lycopersicum L.) Seedlings in Hydroponic Systems.

Seven auxin-producing endophytic bacterial strains (Azospirillum spp., Methylobacterium symbioticum, Bacillus spp.), and two different combinations of these strains were used to verify their influence on tomato during germination and development in hydroponic conditions where, as a novelty for Canestrino di Lucca cultivar, endophytic bacteria were inoculated. To emphasize the presence of bacterial auxins in roots and stems of seedlings, both in situ staining qualitative assessment and quantitative analysis were carried out. Moreover, hypogeal and epigeal growth of the plantlets were measured, and correlation analyses were conducted to examine the relationship between the amount of indolacetic acid (IAA) produced by the bacterial strains and root and stem parameters. Plantlets treated with microbial inoculants showed a significant increase in the survival rate compared to the control treatment. The best results as IAA producers were from Azospirillum baldaniorum Sp245 and A. brasilense Cd, which also induced significant root growth. On the other hand, Bacillus amyloliquefaciens and B. licheniformis induced the best rates in stem growth. These findings highlight the potential for using endophytic bacterial strains in a hydroponic co-cultivation system that enables inoculating plantlets, at an early stage of growth (5 days old).

From the perspective of world heritage, the strategy and sustainable development of the mushroom co-cultivation system in Qingyuanlin (Zhejiang)

The Qingyuan Forest-Mushroom Co-culture System in Zhejiang Province, China, located in Qingyuan County, Lishui City, was recognized as a Globally Important Agricultural Heritage System (GIAHS) in 2022. In this study, the author compares the selection criteria and characteristics of the “Zhejiang Qingyuan Forest-Mushroom Co-cultivation System” with those of other World Agricultural Heritage sites. Through an in-depth analysis of the uniqueness of the “Zhejiang Qingyuan Forest-Mushroom Co-cultivation System” and its ecological, economic, and cultural values, the author aims to reveal its advantages in the World Heritage List and explore reasonable ways for its sustainable development.

Bioplastic Compounds of Succinic Acid from Agriculture Waste; Date Palm Syrup And Date Palm Fronds

Excessive use of petrochemical-based plastics lead to severe plastic pollution by accumulation in soil, drainage system blockage, also each year trillions of plastic residues released into the ocean. In some cases, burning plastic waste releases toxic gases and may cause acid rain. Bioplastics, biodegradable, are eco-friendly alternatives to petroleum-based plastics, reduce environmental impacts and utilize non-edible waste products for decomposition by microorganisms, making them a significant topic in the twenty-first century. Succinic acid has wide medical and industrial application, in addition to being a solution to the problem of plastic pollution for use in the manufacture of bioplastics. One of the most important biomass wastes in the Iraqi environment that are candidates for biorefinery is palm waste due to its environmental friendliness and high sugar content. In this study, succinic acid was investigated in the fermentation product of poor-quality date palms Zahid and palm fronds. The residues of Zahid dates with palm fronds and the addition of soybean were used for the production of succinic through the process of batch fermentation and solid-state fermentation using a mixture of yeasts Saccharomyces cerevisiae and P. stipitis ATCC 58785 and fungi Trichoderma reesei and Aspergillus niger after pretreatment. The succinic acid was estimated using GC mass, and the quantities of acid produced from date juice from Zuhdi dates syrup were 20.6g/L, while the optimal ratio of acid produced from palm fronds with soybeans was estimated at 2.28g/L and production improved to 3.51 g/L by fed batch fermentation. Biotonic acid, oxalic acid malic acid were detected in significant amount as 10.82,23.68 and 70.40 g/L respectively from date syrup. This research opens the horizons for the use of the biomass of the dates palm in the production of bioplastics. Consolidated bioprocessing of lignocellulose to succinic acid through a microbial cocultivation system consolidated bioprocessing.

Pseudomonas putida as saviour for troubled Synechococcus elongatus in a synthetic co-culture – interaction studies based on a multi-OMICs approach

In their natural habitats, microbes rarely exist in isolation; instead, they thrive in consortia, where various interactions occur. In this study, a defined synthetic co-culture of the cyanobacterium S. elongatus cscB, which supplies sucrose to the heterotrophic P. putida cscRABY, is investigated to identify potential interactions. Initial experiments reveal a remarkable growth-promoting effect of the heterotrophic partner on the cyanobacterium, resulting in an up to 80% increase in the growth rate and enhanced photosynthetic capacity. Vice versa, the presence of the cyanobacterium has a neutral effect on P. putida cscRABY, highlighting the resilience of pseudomonads against stress and their potential as co-culture partners. Next, a suitable reference process reinforcing the growth-promoting effect is established in a parallel photobioreactor system, which sets the basis for the analysis of the co-culture at the transcriptome, proteome, and metabolome levels. In addition to several moderate changes, including alterations in the metabolism and stress response in both microbes, this comprehensive multi-OMICs approach strongly hints towards the exchange of further molecules beyond the unidirectional feeding with sucrose. Taken together, these findings provide valuable insights into the complex dynamics between both co-culture partners, indicating multi-level interactions, which can be employed for further streamlining of the co-cultivation system.

Evalution of co-culture system on Debaryomyces hansenii and Bacillus atrophaeus strains and its efficacy on disease control and quality maintenance of postharvest fruit

Microbial antagonists are used to manage both pre- and postharvest diseases of fruit crops. Mixing two types of antagonists has been reported to enhance the viability, stability, and biocontrol efficacy of each strain used individually. In the present study, a co-cultivation system for Debaryomyces hansenii (Y-1) and Bacillus atrophaeus (TE-7) strains was evaluated, and the regulatory mechanism associated with antagonistic activity and postharvest disease control in mango and litchi fruits was investigated. Results indicated that the optimized co-cultivation system for Y-1 and TE-7 (Y + T) significantly promoted the growth of both strains, compared to single cultures, and improved their ability to adapt to co-cultivation conditions. Non-targeted metabolomics revealed that characteristic metabolites, including N-Acetyl-L-glutamic acid, adenine, umbelliferone, and cucurbitacin B significantly accumulated in co-culture, which involved in citrate cycle (TCA cycle), amino acid biosynthesis, phenylpropanoid biosynthesis, and alkaloid biosynthesis. Subsequent in vivo and in vitro assays indicated that the Y + T system, relative to the use of the individual strains, significantly enhanced the inhibition of pathogen growth, increased disease control, and also decreased weight loss and changes in peel color. The co-culture also enhanced the content of total acids (TA) and total soluble solids (TSS) in mango and litchi fruits compared to the control group. These results suggest that the Y + T co-cultivation system is highly effective in antagonistic protection, disease control, and quality maintenance of postharvest fruit. Our study provides new insights into the interactions that occur between biocontrol microorganisms in a co-culture system, and information that can be used for the development of improved strategies for the postharvest preservation of fruit.

Potential of house crickets Acheta domesticus L. (Orthoptera: Gryllidae) as a novel food source for integration in a co-cultivation system

Environmental controlled indoor cultivation combined with a co-cultivation of different organisms can address the challenges of agri-food systems and lead towards resilience. Due to their numerous food and feed applications and low environmental impact, house crickets (Achaeta domesticus) are a promising candidate for indoor cultivation systems. The present study explored the potential of house crickets for application in indoor farming and co-cultivation systems, by applying PAR at elevated intensity combined with narrowband UV-B irradiation at 285 nm and observing its effect on the development of the house crickets, their nutritional composition and the mineral content of their frass, which has potential as fertilizer. Narrowband UV-B irradiation increased the survival rate of the house crickets by >20%, while not affecting their weight (g/cricket), compared to house crickets reared in the same conditions without the narrowband UV-B irradiation (Elevated PAR). Furthermore, narrowband UV-B irradiation increased by 16.18% and 67.95% the protein and chitin content, respectively, compared to the house crickets reared in the same conditions without UV-B irradiation. Finally, all the frass samples showed a rich mineral profile containing Ca, K, Mg, Na and S, with narrowband UV-B irradiation affecting its composition throughout the rearing process. Thus, this study demonstrates that house crickets can adapt physiologically to different environments and are suitable for integration into indoor farming and co-cultivation systems. Thus, it is suggested that house crickets, as edible insects, have significant potential to be cultivated with other organisms, an important step for the circular economy.

An Innovative Co-Cultivation of Microalgae and Actinomycete-Inoculated Lettuce in a Hydroponic Deep-Water Culture System for the Sustainable Development of a Food–Agriculture–Energy Nexus

In recent years, researchers have turned their attention to the co-cultivation of microalgae and plants as a means to enhance the growth of hydroponically cultivated plants while concurrently producing microalgal biomass. However, the techniques used require precise calibration based on plant growth responses and their interactions with the environment and cultivation conditions. This study initially focused on examining the impact of hydroponic nutrient concentrations on the growth of the microalga Chlorella sp. AARL G049. The findings revealed that hydroponic nutrient solutions with electrical conductivities (EC) of 450 µS/cm and 900 µS/cm elicited a positive response in microalgae growth, resulting in high-quality biomass characterized by an elevated lipid content and favorable properties for renewable biodiesel. The biomass also exhibited high levels of polyunsaturated fatty acids (PUFAs), indicating excellent nutritional indices. The microalgae culture and microalgae-free culture, along with inoculation-free lettuce (Lactuca sativa L. var. longifolia) and lettuce that was inoculated with plant growth actinobacteria, specifically the actinomycete Streptomyces thermocarboxydus S3, were subsequently integrated into a hydroponic deep-water culture system. The results indicated that several growth parameters of lettuce cultivated in treatments incorporating microalgae experienced a reduction of approximately 50% compared to treatments without microalgae, and lowering EC levels in the nutrient solution from 900 µS/cm to 450 µS/cm resulted in a similar approximately 50% reduction in lettuce growth. Nevertheless, the adverse impacts of microalgae and nutrient stress were alleviated through the inoculation with actinomycetes. Even though the co-cultivation system leads to reduced lettuce growth, the system enables the production of high-value microalgal biomass with exceptional biodiesel fuel properties, including superior oxidative stability (&gt;13 h), a commendable cetane number (&gt;62), and a high heating value (&gt;40 MJ/kg). This biomass, with its potential as a renewable biodiesel feedstock, has the capacity to augment the overall profitability of the process. Hence, the co-cultivation of microalgae and actinomycete-inoculated lettuce appears to be a viable approach not only for hydroponic lettuce cultivation but also for the generation of microalgal biomass with potential applications in renewable energy.

Construction of an efficient microalgal-fungal co-cultivation system for swine wastewater treatment: Nutrients removal and extracellular polymeric substances (EPS)-mediated aggregated structure formation

Microalgal-fungal co-cultivation technology has demonstrated outstanding efficacy in wastewater treatment and valuable resources recovery. However, it is still unclear how extracellular polymeric substances (EPS) could potentially affect the formation and development of co-cultivation aggregates. In this work, efficient microalgal-fungal co-cultivation systems (MFCS) were developed for swine wastewater treatment. Different co-cultivation systems were established using various microalgae (Chlorella sorokiniana and Scenedesmus dimorphus) with fungi (Aspergillus oryzae or Aspergillus niger). The results showed that the introduction of fungi improved nutrient removal, and C. sorokiniana-A. oryzae co-cultivation system demonstrated the highest removal efficiency for chemical oxygen demand (COD) (85.9 %), ammonium (NH4+-N) (76.5 %), and total phosphorus (TP) (60.3 %). Biomass production in co-cultivation system was higher, and S. dimorphus-A. oryzae co-cultivation system achieved the highest biomass production of 0.74 g/L. In addition, the lipid content in co-cultivation system was up to 33.3 %, which was 1.8 times higher than that in the mono-cultivation group. Besides biomass production, A. oryzae also promoted the photosynthetic activity of C. sorokiniana, showing higher pigments content and electron transport efficiency. The morphology of co-cultivation systems displayed complex interactions between fungi and microalgae, forming aggregated structures. The analysis of EPS demonstrated their importance in the formation and stabilization of microalgae-fungal aggregates. Moreover, proteins and polysaccharides, along with chemical bonds (N-H, C = O and C-O-C), played a crucial role in the formation and development of aggregates. This study provides insights into the potential of MFCS for swine wastewater treatment, highlighting the importance of species selection and EPS-mediated interactions in enhancing system performance.

Copper regulates degradation of typical antibiotics by microalgal-fungal consortium in simulated swine wastewater: insights into metabolic routes and dissolved organic matters

Microalgae-based biotechnology for antibiotics biodegradation in swine wastewater has been receiving an increasing attention. In this study, microalgae and fungi co-cultivation system, regulated by copper (Cu(II)), was investigated in terms of nutrients and sulfonamides degradation in simulated swine wastewater. Results showed that the removal of ammonium nitrogen (NH4+-N), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) by microalgal-fungal consortium increased under 0.1-0.5 mg/L Cu(II) with the highest removal efficiency of 79.19%, 76.18%, 93.93% and 93.46%, respectively. The addition of Cu(II) (0-0.5 mg/L) enhanced the removal of sulfamonomethoxine (SMM), sulfamethoxazole (SMX) and sulfamethazine (SMZ) from 49.05% to 58.76%, from 59.31% to 63.51%, and from 37.51% to 63.9%, respectively, and the main removal mechanism was found to be biodegradation. Biodegradation followed a pseudo-first-order model with variable half-lives (10.12 to 15.51 days for SMM, 9.01 to 10.88 days for SMX, and 8.74 to 12.85 days for SMZ). Through mass spectrometry analysis, metabolites and intermediates of sulfonamides were accordingly identified, suggesting that the degradation routes were involved with hydroxylation, deamination, oxidation, de-sulfonation and bond cleavage. Dissolved organic matters released by microalgal-fungal consortium were induced by Cu(II). Fulvic acid-like and protein-like substances were bound to Cu(II), reducing its concentration and thus mitigating the organismal damage to microorganisms. These findings drew an insightful understanding of microalgal-fungal consortium for sulfonamides remediation by Cu(II) regulation in simulated swine wastewater.

Does conservation tillage adoption improve farmers’ agricultural income? A case study of the rice and fish co-cultivation system in Jianghan Plain, China

This study analyses the income effects of farm households' conservation tillage adoption on agricultural income in China. Based on survey data of 704 farm households from Jianghan Plain, central China, Heckman two-stage and propensity score matching models are employed to quantitatively measure the income effect of farm households' adoption of rice and fish co-cultivation, including six aquatic animals. The results reveal that most farmers have adopted rice and fish co-cultivation methods, but with limited adoption intensity. The number of farmers engaged in co-cultivation and farmers' degree of knowledge and cognition significantly influence adoption and increase adoption intensity. Compared with the non-adoption group, the agricultural income of rice and fish co-cultivation system adoption improved adopters’ incomes by 35.15%. In conclusion, rice and fish co-cultivation publicity, technical training and compensation are highly beneficial and recommended.

Elimination of Residual Lacto-N-triose II for Lacto-N-tetraose Biosynthesis in Engineered Escherichia coli.

Lacto-N-tetraose (LNT) is an important neutral human milk oligosaccharide (HMO) and acts as a significant core structure for complex HMO biosynthesis. We previously achieved high-yield LNT biosynthesis (57.5 g/L) using fed-batch fermentation; however, residual lacto-N-triose II (LNTri II) was also found (21.58 g/L). Here, we re-engineered an efficient LNT-producing Escherichia coli with low LNTri II accumulation using genetically stable LNTri II-producing strains with a genomic insertion of lgtA (encoding β1,3-N-acetylglucosaminyltransferase). Comparable and low titers of LNT (3.73-4.61 g/L) and LNTri II (0.33-0.63 g/L), respectively, were obtained by introducing β1,3-galactosyltransferase. To reduce residual LNTri II, the E. coli transporter gene setA was disrupted, obviously reducing the accumulation of LNTri II and LNT. Next, the gene encoding β-N-acetylhexosaminidase (BbhI) was introduced into LNT-producing strains or E. coli BL21(DE3) for single- or mixed-strain cultivation, respectively. Finally, LNT was obtained (30.13 g/L) in a cocultivation system of mixed engineered strains without undesired LNTri II.

Nodakenin Inhibits Melanogenesis Via the ERK/MSK1 Signaling Pathway.

The aim of the present study was to investigate the potential inhibitory effects of nodakenin, a coumarin glucoside derivative from the root extract of Angelica gigas Nakai (AGN), on melanogenesis and its underlying mechanisms in B16F10 melanoma cells. The inhibitory effects of nodakenin on melanogenesis were evaluated by determining melanin contents and tyrosinase activity in α -melanocyte stimulating hormone (α-MSH)-treated B16F10 melanoma cells. The mechanisms associated with the anti-pigmentation effect of nodakenin were investigated by quantitative real-time PCR and immunoblotting analysis. Using the UVB-irradiated conditioned media culture system and UVB-irradiated co-cultivation system of HaCaT keratinocytes and B16F10 melanoma cells mimicking in vivo melanin biosynthesis, the effect of nodakenin on melanin production was evaluated. Melanin content analysis showed that nodakenin decreased cellular melanin biosynthesis in α-MSH-treated B16F10 cells. Immunoblotting revealed that CREB phosphorylation, MITF, a mastering transcription factor of melanogenesis and its downstream genes tyrosinase, tyrosinase-related protein 1, and tyrosinase-related protein 2 were downregulated by nodakenin in a dose-dependent manner. Interestingly, nodakenin did not affect the phosphorylation of PKA and p38 MAPK but the phosphorylation of ERK1/2 and MSK1. In addition, the inhibition of melanin accumulation by nodakenin in the UVB-irradiated conditioned media culture system and UVB-irradiated co-cultivation system of HaCaT and B16F10 cells suggests that nodakenin has potential as an anti-pigmentation activity. These data suggest that nodakenin inhibits the melanogenesis in B16F10 cells by interfering the ERK/ MSK1/CREB axis and thus preventing MITF expression.

Cultivating the Mediterranean Wild Edible Species Cichorium spinosum L. in Aquaponics: Functional and Growth Responses to Minimal Nutrient Supplementation

Aquaponics is a plant and fish co-cultivation system with high sustainability, yet sub-optimal concentrations of Fe and K often compromise crop yields. We cultivated the Mediterranean wild edible Cichorium spinosum L. (Greek name: stamnagathi) in an aquaponics setup following a minimal supplementation approach that focused on Fe and K. Stamnagathi and tilapia fish were co-cultivated under (i) solely Fe, (ii) Fe+K input and (iii) no-input Control treatments. We aimed to evaluate the feasibility of aquaponics for stamnagathi cultivation, identify the system’s bottlenecks, and propose optimization measures. Several plant’s growth and functional parameters were monitored throughout the 35-day experimental period, notably instantaneous gas exchange and photosynthetic capacity via light response curves, state and efficiency of the photosynthetic machinery, pigment content, and yield and morphometric assessments. Fish growth characteristics and survival rates remained unaffected. Fe deficiency was crucial in shaping the responses of Control stamnagathi, which showed inferior performance in terms of photochemistry, chlorophylls content, light use efficiency and, subsequently, photosynthetic activity. Fe and Fe+K-treated plants exhibited similarly high performance in all studied parameters and achieved 4.5- and 4-fold increased yields, respectively, compared to Control. The results demonstrate that aquaponics is an advantageous cropping system for stamnagathi and solely Fe supplementation is adequate to promote excellent performance and yield of this oligotrophic species.

Photobiological production of high-value pigments via compartmentalized co-cultures using Ca-alginate hydrogels

Engineered cyanobacterium Synechococcus elongatus can use light and CO2 to produce sucrose, making it a promising candidate for use in co-cultures with heterotrophic workhorses. However, this process is challenged by the mutual stresses generated from the multispecies microbial culture. Here we demonstrate an ecosystem where S. elongatus is freely grown in a photo-bioreactor (PBR) containing an engineered heterotrophic workhorse (either β-carotene-producing Yarrowia lipolytica or indigoidine-producing Pseudomonas putida) encapsulated in calcium-alginate hydrogel beads. The encapsulation prevents growth interference, allowing the cyanobacterial culture to produce high sucrose concentrations enabling the production of indigoidine and β-carotene in the heterotroph. Our experimental PBRs yielded an indigoidine titer of 7.5 g/L hydrogel and a β-carotene titer of 1.3 g/L hydrogel, amounts 15–22-fold higher than in a comparable co-culture without encapsulation. Moreover, 13C-metabolite analysis and protein overexpression tests indicated that the hydrogel beads provided a favorable microenvironment where the cell metabolism inside the hydrogel was comparable to that in a free culture. Finally, the heterotroph-containing hydrogels were easily harvested and dissolved by EDTA for product recovery, while the cyanobacterial culture itself could be reused for the next batch of immobilized heterotrophs. This co-cultivation and hydrogel encapsulation system is a successful demonstration of bioprocess optimization under photobioreactor conditions.

Miracula blauvikensis: a new species of Miracula from Iceland, and report of a co-cultivation system for studying oomycete-diatom interactions.

The genus Miracula represents an early-diverging lineage of diatom-parasitic Oomycota, straminipilous eukaryotes that have evolved fungal features independent from the opisthokont Fungi. Recent studies have revealed that diatom parasitoids are much more species-rich than previously thought and may play an important role in limnic and marine ecosystems. Of the different diatom-parasitic lineages, the genus Miracula is one of the most abundant in marine ecosystems. Here a species of Miracula parasitising Fragilaria capucina s.l. from Iceland is described as Miracula blauvikensis. In addition, its phylogenetic position is clarified and its life-cycle documented. The species has been brought into co-cultivation with its host, and due to the ease of cultivation and the convenient microscopy of the diatom threads, this co-culture might be a useful tool to study oomycete-diatom interactions in the future. Citation: Buaya A, Thines M (2022). Miracula blauvikensis: a new species of Miracula from Iceland, and report of a co-cultivation system for studying oomycete-diatom interactions. Fungal Systematics and Evolution 10: 169-175. doi: 10.3114/fuse.2022.10.07.

Symbiotic association of microalgae and plants in a deep water culture system.

In this study, microalgae culture (Chlorella vulgaris) and mint seedlings (Mentha spp.) were combined in a hydroponic system to improve plant growth. Mint seedlings were grown both in microalgae-containing and in microalgae-free trial groups, and both groups were subjected to aerated and non-aerated conditions to show the effect of aeration and microalgae co-cultivation on the mint weight and height. The plant quality was also determined with color measurements of the mint leaves. The increase in the weight of the plants was the highest in microalgae-containing and aerated group (0.47 g) and the lowest in microalgae-free and non-aerated group (0.22 g). On the other hand, the variation in the plant height was not significant between the groups, the growth was lateral. The best quality mint leaves were also produced in microalgae-containing and aerated group. Our results have revealed the symbiotic life of the mint plant placed in the hydroponic system with microalgae and demonstrated improved mint growth and quality. This co-cultivation system is also potentially more environmentally friendly compared to growing microalgae and mint independently because of lower cost of aeration and mixing for microalgae cultivation, higher nutrient consumption efficiency, and reduced nutrient outflow.

Characteristics and Resistance to Cisplatin of Human Neuroblastoma Cells Co-Cultivated with Immune and Stromal Cells.

We investigated the features of the morphology and cytokine profiles of neuroblastoma SH-SY5Y cells, bone marrow-derived mesenchymal stromal/stem cells (BM-MSCs), and peripheral blood mononuclear cells (PBMCs) in double (BM-MSCs + SH-SY5Y cells) and triple (BM-MSCs + SH-SY5Y cells + PBMCs) co-cultures incubated on plastic and Matrigel. Cells in the co-cultures communicated by vesicular transport and by exchanging membrane and cytoplasmic components. The cytokine profile of double and triple co-cultures incubated on Matrigel and plastic had differences and showed the highest concentration of a number of chemokines/cytokines, such as CXCL8/IL-8, I-TAC/CXCL11, IP10/CXCL10, MDC/CCL22, MIP-1α/CCL3, IL-1β, ENA-78/CXCL5, Gro-α/CXCL1, MCP-1/CCL2, TERC/CCL25, CXCL8/IL-8, and IL-6. High concentrations of inflammatory chemokines/cytokines in the conditioned medium of triple co-culture form a chronic inflammation, which brings the presented co-cultivation system closer to a natural tumor. Triple co-cultures were more resistant to cisplatin (CDDP) than the double- and monoculture of SH-SY5Y. The mRNA levels of BCL2, BCL2L1, RAC1, CAV1, CASP3, and BAX genes were changed in cells after co-culturing and CDDP treatment in double and triple co-cultures. The expression of the BCL2, BAX, CAV1, and CASP3 proteins in SH-SY5Y cells after the triple co-culture and CAV1 and BAX protein expression in SH-SY5Y cells after the double co-culture were determined. This study demonstrated the nature of the cellular interactions between components of tumor niche and the intercellular influence on chemoresistance observed in our tumor model, which should enable the development of novel test systems for anti-tumor agents.

Advanced "Green" Prebiotic Composite of Bacterial Cellulose/Pullulan Based on Synthetic Biology-Powered Microbial Coculture Strategy.

Bacterial cellulose (BC) is a biopolymer produced by different microorganisms, but in biotechnological practice, Komagataeibacter xylinus is used. The micro- and nanofibrillar structure of BC, which forms many different-sized pores, creates prerequisites for the introduction of other polymers into it, including those synthesized by other microorganisms. The study aims to develop a cocultivation system of BC and prebiotic producers to obtain BC-based composite material with prebiotic activity. In this study, pullulan (PUL) was found to stimulate the growth of the probiotic strain Lactobacillus rhamnosus GG better than the other microbial polysaccharides gellan and xanthan. BC/PUL biocomposite with prebiotic properties was obtained by cocultivation of Komagataeibacter xylinus and Aureobasidium pullulans, BC and PUL producers respectively, on molasses medium. The inclusion of PUL in BC is proved gravimetrically by scanning electron microscopy and by Fourier transformed infrared spectroscopy. Cocultivation demonstrated a composite effect on the aggregation and binding of BC fibers, which led to a significant improvement in mechanical properties. The developed approach for “grafting” of prebiotic activity on BC allows preparation of environmentally friendly composites of better quality.