Asbestos poses a substantial environmental health risk, and biological treatment offers a promising approach to mitigate its impact by altering its chemical composition. However, the dynamics of microbial co-inoculation in asbestos bioremediation remain poorly understood. This study investigates the effect of microbial single cultures and co-cultures on modifying crocidolite and chrysotile fibers, focusing on the extraction of iron and magnesium. Seventy bacterial and eighty-three fungal strains were isolated from five diverse sites, characterized phylogenetically using the 16S rRNA and ITS regions, respectively, and assessed for siderophore and organic acid production. Most bacterial strains were identified as Pseudomonas, while Penicillium predominated among fungal strains. Ten bacterial and 25 fungal strains were found to produce both organic compounds. Four microbial co-cultures (one bacterium-bacterium, two fungus-bacterium, and one fungus-fungus) exhibiting synergistic effects in plate assays, alongside their respective single cultures, were incubated with crocidolite and chrysotile. ICP-OES analysis revealed that in crocidolite, the co-culture HRF19-HRB12 removed more iron than their single cultures, while Penicillium TPF36 showed the highest iron removal. The co-culture of two Pseudomonas strains (HRB12-RB5) exhibited the highest magnesium concentration in the supernatant. In chrysotile, the co-culture HRB12-RB5 removed more iron than their individual cultures, with Penicillium TFSF27 exhibiting the highest iron concentration in solution. Penicillium TFSF27 and the co-culture TFSF27-TPF36 demonstrated the highest magnesium removal. SEM-XRMA analysis showed a significant reduction in iron and magnesium content, confirming elemental extraction from the fibers\' structure. This study significantly broadens the range of microbial strains capable of modifying asbestos fibers and underscores the potential of microbial co-cultures in asbestos remediation.

In Chile, Piscirickettsia salmonis contains two genetically isolated genogroups, LF-89 and EM-90. However, the impact of a potential co-infection with these two variants on Salmonid Rickettsial Septicemia (SRS) in Atlantic salmon (Salmo salar) remains largely unexplored. In our study, we evaluated the effect of P. salmonis LF-89-like and EM-90-like co-infection on post-smolt Atlantic salmon after an intraperitoneal challenge to compare changes in disease dynamics and host immune response. Co-infected fish had a significantly lower survival rate (24.1%) at 21 days post-challenge (dpc), compared with EM-90-like single-infected fish (40.3%). In contrast, all the LF-89-like single-infected fish survived. In addition, co-infected fish presented a higher presence of clinical lesions than any of the single-infected fish. The gene expression of salmon immune-related biomarkers evaluated in the head kidney, spleen, and liver showed that the EM-90-like isolate and the co-infection induced the up-regulation of cytokines (e.g., il-1β, ifnγ, il8, il10), antimicrobial peptides (hepdicin) and pattern recognition receptors (PRRs), such as TLR5s. Furthermore, in serum samples from EM-90-like and co-infected fish, an increase in the total IgM level was observed. Interestingly, specific IgM against P. salmonis showed greater detection of EM-90-like antigens in LF-89-like infected fish serum (cross-reaction). These data provide evidence that P. salmonis LF-89-like and EM-90-like interactions can modulate SRS disease dynamics in Atlantic salmon, causing a synergistic effect that increases the severity of the disease and the mortality rate of the fish. Overall, this study contributes to achieving a better understanding of P. salmonis population dynamics.

Halogenated organic compounds are persistent pollutants that pose a serious threat to human health and the safety of ecosystems. Cobamides are essential cofactors for reductive dehalogenases (RDase) in organohalide-respiring bacteria (OHRB), which catalyze the dehalogenation process. This review systematically summarizes the impact of cobamides on organohalide respiration. The catalytic processes of cobamide in dehalogenation processes are also discussed. Additionally, we examine OHRB, which cannot synthesize cobamide and must obtain it from the environment through a salvage pathway; the co-culture with cobamide producer is more beneficial and possible. This review aims to help readers better understand the importance and function of cobamides in reductive dehalogenation. The presented information can aid in the development of bioremediation strategies.

Macrophages, as the largest immune cell group in tumour tissues, play a crucial role in influencing various malignant behaviours of tumour cells and tumour immune evasion. As the research on macrophages and cancer immunotherapy develops, the importance of appropriate research models becomes increasingly evident. The development of organoids has bridged the gap between traditional two-dimensional (2D) cultures and animal experiments. Recent studies have demonstrated that organoids exhibit similar physiological characteristics to the source tissue and closely resemble the in vivo genome and molecular markers of the source tissue or organ. However, organoids still lack an immune component. Developing a co-culture model of organoids and macrophages is crucial for studying the interaction and mechanisms between tumour cells and macrophages. This paper presents an overview of the establishment of co-culture models, the current research status of organoid macrophage interactions, and the current status of immunotherapy. In addition, the application prospects and shortcomings of the model are explained. Ultimately, it is hoped that the co-culture model will offer a preclinical testing platform for maximising a precise cancer immunotherapy strategy.

Cultured meat, an emerging meat production technology, has reduced environmental burden as well as provide healthier and more sustainable method of meat culture. Fat in cultured meat is essential for enhancing texture, taste, and tenderness. However, current cultured meat production method is limited to single-cell type. To meet the consumer demands for cultured meat products, it is crucial to develop new methods for producing cultured meat products that contain both muscle and fat. In this study, cell viability and differentiation were promoted by controlling the ratio and cultivation conditions of myocytes and adipocytes. The total digestibility of cultured meat exceeded 37%, higher than that of beef (34.7%). Additionally, the texture, appearance, and taste of the co-cultured meat were improved. Collectively, this research has great promise for preparing rich-nutritious and digestion cultured meat.

The rising utilization of PLA/PBAT-ST20 presents potential ecological risks stemming from its casual disposal and incomplete degradation. To solve this problem, this study investigated the degradation capabilities of PLA/PBAT-ST20 by a co-culture system comprising two thermophilic bacteria, Pseudomonas G1 and Kocuria G2, selected and identified from the thermophilic phase of compost. Structural characterization results revealed that the strains colonized the PLA/PBAT-ST20\'s surface, causing holes and cracks, with an increase in the carbonyl index (CI) and polydispersity index (PDI), indicating oxidative degradation. Enzyme activity results demonstrated that the co-culture system significantly enhanced the secretion and activity of proteases and lipases, promoting the breakdown of ester bonds. LC-QTOF-MS results showed that various intermediate products were obtained after degradation, ultimately participating in the TCA cycle (ko00020), further completely mineralized. Additionally, after 15-day compost, the co-culture system achieved a degradation rate of 72.14 ± 2.1 wt% for PBAT/PLA-ST20 films, with a decrease in the abundance of plastic fragments of all sizes, demonstrating efficient degradation of PLA/PBAT-ST20 films. This study highlights the potential of thermophilic bacteria to address plastic pollution through biodegradation and emphasizes that the co-culture system could serve as an ideal solution for the remediation of PLA/PBAT plastics.

The genus Nocardia are gram-positive bacteria, many of which possess pathogenicity and infect human lungs, skin, brain, and other organs. Since research on the genus Nocardia has not progressed as rapidly as that on the genus Streptomyces, the genus Nocardia is considered a useful undeveloped resource for exploring natural products. On the other hand, when the genus Nocardia infects the human body, the strains are attacked by immune cells such as macrophages. Therefore, we suggested a new method for screening natural products by culturing the genus Nocardia in the presence of animal cells. In this review, we describe our recent results in searching for natural products from the genus Nocardia.

OBJECTIVE: Osteosarcoma is a primary bone tumor lacking optimal clinical treatment options. Tumor-associated macrophages in the tumor microenvironment are closely associated with tumor development and metastasis. Studies have identified the macrophage receptor with collagenous structure (MARCO) as a specific receptor expressed in macrophages. This study aimed to investigate whether anti-MARCO mAb treatment can induce macrophage polarization in the tumor microenvironment and elicit anti-tumor effects.
METHODS: THP-1 cells were treated with 20 ng/mL phorbol 12-myristate 13-acetate and 80 ng/mL interleukin-4 for 48 h to induce macrophage polarization to alternatively activated macrophages (M2). Enzyme-linked immunosorbent assay, real-time quantitative polymerase chain reaction, flow cytometry, and bioinformatic analyses were performed to evaluate macrophage polarization. The co-culture groups included a blank group, an M2 macrophage and U2OS co-culture group, and an anti-MARCO mAb-treated M2 macrophage group. Cell viability assays, cell scratch tests, apoptosis, and cell cycle analyses were performed to determine the effects of anti-MARCO mAb-treated macrophages on osteosarcoma cells.
RESULTS: It was demonstrated that anti-MARCO mAb can drive macrophages toward classically activated macrophage (M1) polarization. Anti-MARCO mAb promoted the secretion of pro-inflammatory factors by macrophages, including tumor necrosis factor-alpha (TNF-α), interleukin-1beta, interleukin-6 and interleukin-23. Studies on in vitro co-culture models have revealed that macrophages treated with anti-MARCO mAb can suppress the growth and migration of osteosarcoma cells, induce cell apoptosis, and inhibit cell cycle progression of osteosarcoma cells through M1 polarization of macrophages in vitro.
CONCLUSIONS: Anti-MARCO mAb treatment exerts anti-osteosarcoma effects by affecting macrophage polarization toward M1 macrophages, offering a potential new therapeutic approach for treating osteosarcoma.

The investigation into viable but non-culturable (VBNC) bacteria through the implementation of resuscitation promoting factors (Rpfs) has broadened the potential sources for isolating strains capable of degrading polychlorinated biphenyls (PCBs). Nonetheless, there has been limited research on the efficacy of resuscitated strains and the potential improvement of their performance through co-cultivation. In this work, the PCB degradation potential of resuscitated strains, specifically Pseudomonas sp. HR1 and Achromobacter sp. HR2, as well as their co-cultures, was investigated. Of particular importance was the comparative analysis between the optimal co-culture and individual strains regarding their ability to degrade PCB homologs and mineralize intermediate metabolites. The results suggested that the resuscitated strains HR1 and HR2 demonstrated robust growth and effective degradation of Aroclor 1242. The co-culture CO13, with an optimal HR1 to HR2 ratio of 1:3, exhibited a remarkable improvement in PCB degradation and intermediate metabolite mineralization compared to individual strains. Analysis of functional genes and degradation metabolites revealed that both the individual strains and co-culture CO13 degraded PCBs via the HOPDA-benzoate pathway, then mineralized through protocatechuate meta- and ortho-cleavage pathways, as well as the catechol ortho-cleavage pathway. This study represents the first documentation of the improved PCB degradation through the co-cultivation of resuscitated strains, which highlights the great promise of these resuscitated strains and their co-cultures as effective bio-inoculants for enhanced bioremediation.

Combined-cultures involving mycolic acid-containing bacteria (MACB) can stimulate secondary metabolite (SM) production in actinomycetes. In a prior investigation, we screened Streptomyces coelicolor JCM4020 mutants with diminished production of SMs, specifically undecylprodigiosin (RED), which was enhanced by introducing the MACB Tsukamurella pulmonis TP-B0596. In this study, we conducted mutational analysis that pinpointed the sco1842 gene, which we assigned the gene name ccr1 (combined-culture related regulatory protein no. 1), as a crucial factor in the deficient phenotype observed in the production of various major SMs in S. coelicolor A3(2). Notably, the Ccr1 (SCO1842) homolog was found to be highly conserved throughout the Streptomyces genome. Although Ccr1 lacked conserved motifs, in-depth examination revealed the presence of a helix-turn-helix (HTH) motif in the N-terminal region and a helicase C-terminal domain (HCTD) motif in the C-terminal region in some of its homologs. Ccr1 was predicted to be a nucleoid-associated protein (NAP), and its impact on gene transcription was validated by RNA-seq analysis that revealed genome-wide variations. Furthermore, RT-qPCR demonstrated that ccr1 was transcriptionally activated in combined-culture with T. pulmonis, which indicated that Ccr1 is involved in the response to bacterial interaction. We then investigated Streptomyces nigrescens HEK616 in combined-culture, and the knockout mutant of the ccr1 homolog displayed reduced production of streptoaminals and 5aTHQs. This finding reveals that the Ccr1 homolog in Streptomyces species is associated with SM production. Our study elucidates the existence of a new family of NAP-like proteins that evolved in Streptomyces species and play a pivotal role in SM production.