Enhancement of polysaccharides production using microparticle enhanced technology by Paraisaria dubia.

BACKGROUND: Polysaccharides are important active ingredients in Ophiocordyceps gracilis with many physiological functions. It can be obtained from the submerged fermentation by the anamorph (Paraisaria dubia) of Ophiocordyceps gracilis. However, it was found that the mycelial pellets of Paraisaria dubia were dense and increased in volume in the process of fermentation, and the center of the pellets was autolysis due to the lack of nutrient delivery, which extremely reduced the yield of polysaccharides. Therefore, it is necessary to excavate a fermentation strategy based on morphological regulation for Paraisaria dubia to promote polysaccharides accumulation. RESULTS: In this study, we developed a method for enhancing polysaccharides production by Paraisaria dubia using microparticle enhanced technology, talc microparticle as morphological inducer, and investigated the enhancement mechanisms by transcriptomics. The optimal size and dose of talc were found to be 2000 mesh and 15 g/L, which resulted in a high polysaccharides yield. It was found that the efficient synthesis of polysaccharides requires an appropriate mycelial morphology through morphological analysis of mycelial pellets. And, the polysaccharides synthesis was found to mainly rely on the ABC transporter-dependent pathway revealed by transcriptomics. This method was also showed excellent robustness in 5-L bioreactor, the maximum yields of intracellular polysaccharide and exopolysaccharides were 83.23 ± 1.4 and 518.50 ± 4.1 mg/L, respectively. And, the fermented polysaccharides were stable and showed excellent biological activity. CONCLUSIONS: This study provides a feasible strategy for the efficient preparation of cordyceps polysaccharides via submerged fermentation with talc microparticles, which may also be applicable to similar macrofungi.

Rapid and concise quantification of mycelial growth by microscopic image intensity model and application to mass cultivation of fungi.

The microbial food fermentation industry requires real-time monitoring and accurate quantification of cells. However, filamentous fungi are difficult to quantify as they have complex cell types such as pellet, spores, and dispersed hyphae. In this study, numerous data of microscopic image intensity (MII) were used to develop a simple and accurate quantification method of Cordyceps mycelium. The dry cell weight (DCW) of the sample collected during the fermentation was measured. In addition, the intensity values were obtained through the ImageJ program after converting the microscopic images. The prediction model obtained by analyzing the correlation between MII and DCW was evaluated through a simple linear regression method and found to be statistically significant (R2 = 0.941, p < 0.001). In addition, validation with randomly selected samples showed significant accuracy, thus, this model is expected to be used as a valuable tool for predicting and quantifying fungal growth in various industries.

Molecular and comparative genomic analyses reveal evolutionarily conserved and unique features of the Schizosaccharomyces japonicus mycelial growth and the underlying genomic changes.

Fungal pathogens, from phytopathogenic fungus to human pathogens, are able to alternate between the yeast-like form and filamentous forms. This morphological transition (dimorphism) is in close connection with their pathogenic lifestyles and with their responses to changing environmental conditions. The mechanisms governing these morphogenetic conversions are still not fully understood. Therefore, we studied the filamentous growth of the less-known, non-pathogenic dimorphic fission yeast, S. japonicus, which belongs to an ancient and early evolved branch of the Ascomycota. Its RNA sequencing revealed that several hundred genes were up- or down-regulated in the hyphae compared to the yeast-phase cells. These genes belonged to different GO categories, confirming that mycelial growth is a rather complex process. The genes of transport- and metabolic processes appeared especially in high numbers among them. High expression of genes involved in glycolysis and ethanol production was found in the hyphae, while other results pointed to the regulatory role of the protein kinase A (PKA) pathway. The homologues of 49 S. japonicus filament-associated genes were found by sequence alignments also in seven distantly related dimorphic and filamentous species. The comparative genomic analyses between S. japonicus and the closely related but non-dimorphic S. pombe shed some light on the differences in their genomes. All these data can contribute to a better understanding of hyphal growth and those genomic rearrangements that underlie it.

Inhibitory Effect of Osthole from Cnidium monnieri (L.) Cusson on Fusarium oxysporum, a Common Fungal Pathogen of Potato.

Fusarium wilt of potato is one of the most common diseases of potato in China, and is becoming a serious threat in potato production. It has been reported that osthole from Cnidium monnieri (L.) Cusson can inhibit plant pathogens. Here, we test the anti-fungal activity of C. monnieri osthole against Fusarium oxysporum in potatoes. The results showed that at a concentration of 5 mg/mL, osthole was able to obviously inhibit mycelial growth of F. oxysporum. We found that osthole caused changes of mycelial morphology, notably hyphal swelling and darkening. Osthole significantly reduced the spore germination of Fusarium by 57.40%. In addition, osthole also inhibited the growth of other pathogens such as Fusarium moniliforme J. Sheld, Thanatephorus cucumeris Donk, and Alternaria alternata (Fr.) Keissl, but not Alternaria solani Jonesetgrout and Valsa mali Miyabe and G. Yamada. Our results suggest that osthole has considerable potential as an agent for the prevention and treatment of potato Fusarium wilt.

FISHing in fungi: Visualisation of mushroom virus X in the mycelium of Agaricus bisporus by fluorescence in situ hybridisation.

Agaricus bisporus is a commercial mushroom crop susceptible to a disease caused by a complex of viruses known collectively as mushroom virus X (MVX). Symptoms of MVX include bare patches and mushroom cap discolouration (browning) in the fruiting bodies, phenotypes associated with the viruses AbV6 and AbV16, respectively. Limited understanding exists of the localisation and mobilisation of these viruses within the mycelium of A. bisporus. To this end, a non-destructive fluorescence in situ hybridisation (FISH) method was developed for in situ targeting of AbV6 and AbV16 in A. bisporus mycelium. An MVX strain associated with the bare patch disease phenotype revealed predominantly high signal towards the growing edges of cultures when probed for AbV6, with a 'halo-effect' of high signal intensity around putative vacuoles. An MVX strain associated with the browning disease phenotype showed high signal intensities within reticulating networks of hyphae in a highly compartmentalised manner when probed for AbV16. Localisation of the two viruses in MVX-infected cultures appears independent, as both viruses were found in completely discrete areas of the mycelium in differential patterns. FISH detected low level presence of the two viruses, AbV6 and AbV16 in a number of cultures which had tested negative for the viruses by RT-PCR. This suggests that FISH may be more sensitive at detecting viruses at low levels than molecular methods. This study demonstrates that FISH is a powerful tool in the field of mycovirology.

mycelyso - high-throughput analysis of Streptomyces mycelium live cell imaging data.

BACKGROUND: Streptomycetes are filamentous microorganisms of high biotechnological relevance, especially for the production of antibiotics. In submerged cultures, the productivity of these microorganisms is closely linked to their growth morphology. Microfluidic lab-on-a-chip cultivation systems, coupled with automated time-lapse imaging, generate spatio-temporal insights into the mycelium development of streptomycetes, therewith extending the biotechnological toolset by spatio-temporal screening under well-controlled and reproducible conditions. However, the analysis of the complex mycelial structure formation is limited by the extent of manual interventions required during processing of the acquired high-volume image data. These interventions typically lead to high evaluation times and, therewith, limit the analytic throughput and exploitation of microfluidic-based screenings. RESULTS: We present the tool mycelyso (MYCElium anaLYsis SOftware), an image analysis system tailored to fully automated hyphae-level processing of image stacks generated by time-lapse microscopy. With mycelyso, the developing hyphal streptomycete network is automatically segmented and tracked over the cultivation period. Versatile key growth parameters such as mycelium network structure, its development over time, and tip growth rates are extracted. Results are presented in the web-based exploration tool mycelyso Inspector, allowing for user friendly quality control and downstream evaluation of the extracted information. In addition, 2D and 3D visualizations show temporal tracking for detailed inspection of morphological growth behaviors. For ease of getting started with mycelyso, bundled Windows packages as well as Docker images along with tutorial videos are available. CONCLUSION: mycelyso is a well-documented, platform-independent open source toolkit for the automated end-to-end analysis of Streptomyces image stacks. The batch-analysis mode facilitates the rapid and reproducible processing of large microfluidic screenings, and easy extraction of morphological parameters. The objective evaluation of image stacks is possible by reproducible evaluation workflows, useful to unravel correlations between morphological, molecular and process parameters at the hyphae- and mycelium-levels with statistical power.

Rapid and robust identification of clinical isolates of Talaromyces marneffei based on MALDI-TOF mass spectrometry or dimorphism in Galleria mellonella.

Talaromyces marneffei is a thermally dimorphic fungal pathogen that causes serious infections particularly in patients with human immunodeficiency virus (HIV). Although the mould form typically produces a characteristic red-diffusing pigment, and conidia from penicillate heads, several nonpathogenic Talaromyces/Penicillium species are morphologically and phenotypically similar. While those other species do not exhibit thermal dimorphism, conversion of T. marneffei to the distinctive fission yeast form in vitro is arduous and frequently incomplete. Here we show that T. marneffei can be rapidly and unambiguously discriminated from related nonpathogenic Talaromyces/Penicillium spp., either by matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry or conversion to fission yeast after introduction into Galleria mellonella. Conversion of T. marneffei conidia to the fission yeast form in G. mellonella larvae occurred as early as 24 h post inoculation at 37oC. Identification by MALDI-TOF was possible after supplementation of the commercial Bruker database with in-house mass spectral profiles created from either the yeast or mycelial phase of T. marneffei. In addition, we show that in-house generated mass spectral profiles could be successfully used to identify T. marneffei with a recently published on-line MALDI-TOF database, circumventing the need to create extensive in-house additional databases for rarely encountered fungal pathogens.

Application and Analysis of Rhizopus oryzae Mycelia Extending Characteristic in Solid-state Fermentation for Producing Glucoamylase.

Enhanced application of solid-state fermentation (SSF) in industrial production and the influence of SSF of Rhizopus K1 on glucoamylase productivity were analyzed using the flat band method. A growth model was implemented through SSF of Rhizopus K1 in this experiment, and spectrophotometric method was used to determine glucoamylase activity. Results showed that in bran and potato culture medium with 70% moisture in a loose state, µ of mycelium reached to 0.15 h-1 after 45 h of culture in a thermostatic water bath incubator at 30°C. Under a low-magnification microscope, mycelial cells appeared uniform, bulky with numerous branches, and were not easily ruptured. The generated glucoamylase activity reached to 55 U/g (dry basis). This study has good utilization value for glucoamylase production by Rhizopus in SSF.

Identification and Characterization of Alternaria Species Associated with Moldy Core of Apple in Chile.

Moldy core (MC) of apple is an important disease in Chile, with prevalence observed between 4 and 46% in Fuji, Oregon Spur Red Chief, and Scarlet apple in the 2014-15 and 2015-16 growing seasons. However, there is no information on the identity of the causal agents associated with MC in Chile. The analysis of 653 MC fruit revealed the presence of several genera of filamentous fungi. However, species of Alternaria (67.7%) were by far the most frequently fungi isolated. In total, 41 Alternaria isolates were characterized morphologically and molecularly using Alternaria major allergen Alt a1, calmodulin, and plasma membrane ATPase gene regions. Six small-spored Alternaria spp. were identified; namely, in order of importance, Alternaria tenuissima, A. arborescens, A. alternata, and A. dumosa in sect. Alternaria; A. frumenti in sect. Infectoriae; and A. kordkuyana in sect. Pseudoalternaria. MC symptoms were reproducible and consisted of a light gray to dark olive-green mycelium over the carpel and seed of immature and mature fruit, confirming that the isolates of these Alternaria spp. were pathogenic. These isolates caused brown necrotic lesions with concentric rings on wounded detached apple leaves. This study demonstrated that at least six Alternaria spp. are the cause of MC of apple in Chile. These Alternaria spp. were isolated alone, or with two or more species coexisting in the same fruit. This is the first report of A. tenuissima, A. arborescens, A. frumenti, A. dumosa, and A. kordkuyana associated with MC of apple in Chile and the first report of A. frumenti, A. kordkuyana, and A. dumosa causing MC of apple worldwide.

Peltaster gemmifer: A new species in the sooty blotch and flyspeck species complex from the United States.

Sooty blotch and flyspeck (SBFS) fungi infect the cuticle of fruit, including apple fruit, and produce pigmented colonies. A new member of this fungal complex in the genus Peltaster is described on the basis of molecular and morphological evidence. The SBFS complex is a diverse group of ectophytic fungi that reside primarily within the order Capnodiales. Sooty blotch and flyspeck isolates from apple orchards in the central United States were subjected to parsimony and Bayesian analyses based on the internal transcribed spacer regions of nuc rDNA, the partial translation elongation factor 1-α gene, and the partial mitochondrial small subunit rRNA gene. Phylogenetic analysis delineated a new species, Peltaster gemmifer, from P. cerophilus and P. fructicola. Peltaster gemmifer conidiophores bear primary conidia that produce secondary conidia either through budding or through microcyclic conidiation; these were not seen in cultures of P. cerophilus and P. fructicola. On cellulose membrane that was placed on water agar amended with apple juice, P. gemmifer produced brown to black pycnothyria in a superficial brownish mycelial mat, similar to the colonies produced on apple fruit. Findings from the present study add to the >80 named and putative SBFS species so far described worldwide.

Macro-morphological characterization and kinetics of Mortierella alpina colonies during batch cultivation.

An effective method for research of macro-morphological characterization and its kinetics was developed by studying the macro-morphological characteristics of Mortierella alpina, an oleaginous zygomycete widely used to produce lipids rich in PUFA, in function of culture medium composition and to link morphological features of fungus with the level of lipid production. A number of distinct morphological forms including hollow pellets, fluffy pellets and freely dispersed mycelia were obtained by changing the fermentation factors. By fitting a Logistic curve, the maximum specific growth rate (µmax)was obtained, which determined the final mycelia morphology. µmax of 0.6584 in three kind of morphological forms is the more appropriate. According to the Luedeking-Piret equation fitting, α≠0 and ß≠0, lipid production was partially associated with the hyphal growth, fluffy pellets which turn glucose into lipidwas more effective than the other two kinds of morphological forms.

Determination of the effect of polyamines on an oil-degrading strain of Yarrowia lipolytica using an odc minus mutant.

Yarrowia lipolytica is an ascomycetous dimorphic yeast with immense potential for industrial applications, including bioremediation of crude oil-contaminated environments. It has been shown that a dimorphic marine isolate of Y. lipolytica (var. indica) has significant capacity to degrade fatty acids and alkanes, when in its yeast morphology. It has also been demonstrated that polyamines play an important role in the yeast-to-mycelium transition of different strains of Y. lipolytica that are unable to utilize those carbon sources. To determine the role of polyamines on their capacity to utilize oils and hydrocarbons, on the dimorphic transition, and also on other characteristics of the var. indica strain of Y. lipolytica, we proceeded to obtain ornithine decarboxylase minus (odc-) mutants. These mutants behaved as yeasts independently of the concentrations of putrescine added. Further, they conserved the oil-degrading capacity of the parent strain. The odc- mutant can thus be used in fatty acid degradation, and oil spill remediation with distinct advantages.

Label-free differentially proteomic analysis of interspecific interaction between white-rot fungi highlights oxidative stress response and high metabolic activity.

The laccase production by mycelial antagonistic interaction among white-rot fungi is a very important pathway for lignin degradation research. To gain a better understanding of competitive mechanisms under mycelial antagonistic interaction among three lignin-degrading white-rot basidiomycetes of Trametesversicolor (Tv), Pleurotusostreatus (Po) and Dichomitussqualens (Ds), mycelial morphology and proteins in three co-culture combinations TvPo (Tv cocultivated with Po), PoDs (Po cocultivated with Ds), TvDs (Tv cocultivated with Ds) were compared with corresponding each two mono-cultures. In this study, scanning electron microscopy detection of co-cultures indicated a highly close attachment of fungal hyphae with each other and conidiation could be inhibited under fungal interaction. In addition, a label-free proteomic analysis revealed changes on fungal proteomes existed in their counterpart competitors of co-culture. The maximum number of 1020 differentially expressed proteins (DEPs) were identified in PoDs relative to Po while the minimum number of 367 DEPs were identified in PoDs relative to Ds. Notably, we also found a large number of overexpressed proteins were oxidative stress-related proteins, followed by carbohydrate metabolism-related proteins and energy production-related proteins in all three co-culture combinations compared with control. These results were important for the future exploration of molecular mechanisms underlying lignin-degrading fungal interaction.

Molecular Insights Into Development and Virulence Determinants of Aspergilli: A Proteomic Perspective.

Aspergillus species are the major cause of health concern worldwide in immunocompromised individuals. Opportunistic Aspergilli cause invasive to allergic aspergillosis, whereas non-infectious Aspergilli have contributed to understand the biology of eukaryotic organisms and serve as a model organism. Morphotypes of Aspergilli such as conidia or mycelia/hyphae helped them to survive in favorable or unfavorable environmental conditions. These morphotypes contribute to virulence, pathogenicity and invasion into hosts by excreting proteins, enzymes or toxins. Morphological transition of Aspergillus species has been a critical step to infect host or to colonize on food products. Thus, we reviewed proteins from Aspergilli to understand the biological processes, biochemical, and cellular pathways that are involved in transition and morphogenesis. We majorly analyzed proteomic studies on A. fumigatus, A. flavus, A. terreus, and A. niger to gain insight into mechanisms involved in the transition from conidia to mycelia along with the role of secondary metabolites. Proteome analysis of morphotypes of Aspergilli provided information on key biological pathways required to exit conidial dormancy, consortia of virulent factors and mycotoxins during the transition. The application of proteomic approaches has uncovered the biological processes during development as well as intermediates of secondary metabolite biosynthesis pathway. We listed key proteins/ enzymes or toxins at different morphological types of Aspergillus that could be applicable in discovery of novel therapeutic targets or metabolite based diagnostic markers.

Morphological variants of Moniliophthora roreri on artificial media and the biotroph/necrotroph shift.

Moniliophthora roreri (Mr) causes frosty pod rot of Theobroma cacao in a hemibiotrophic association. The Mr biotroph-like phase has not been studied in culture. Mr spores (isolates Co12, Co52, and B3) were germinated on high (V8) and low (BPMM) nutrients with different media hardness (0.5% to 3% agarose). Germination was high on V8 media. Hardness affected germination on BPMM. Most colonies on V8 were slow-growing, failing to sporulate. Colony morphology depended on the isolate. On BPMM, exaggerated mycelia formed of limited length with enlarged cells. On agarose, rapidly expanding sporulating necrotrophic colonies formed rarely. Co12 and B3 spores were germinated on V8 and BPMM with low melting point (LMP) agarose. Slow-growing colonies of B3 on BPMM were unstable on LMP agarose, often forming slow-growing/rapidly expanding hybrids. Slow-growing colonies are hypothesized to represent the biotrophic phase. One nucleus was common in Mr cells, other than spores. Binucleate cells were occasionally observed in aged cells of slow-growing mycelia. Co52 cells often had more than two nuclei per cell after germination. Mr mycelia cells typically carry a single nucleus, being considered haploid. Biotroph- and necrotroph-like mycelia displayed differential gene expression but results were inconsistent with published in vivo results and require further study.

High temperature induced disruption of the cell wall integrity and structure in Pleurotus ostreatus mycelia.

Fungal cells are surrounded by a tight cell wall to protect them from harmful environmental conditions and to resist lysis. The synthesis and assembly determine the shape, structure, and integrity of the cell wall during the process of mycelial growth and development. High temperature is an important abiotic stress, which affects the synthesis and assembly of cell walls. In the present study, the chitin and ß-1,3-glucan concentrations in the cell wall of Pleurotus ostreatus mycelia were changed after high-temperature treatment. Significantly higher chitin and ß-1,3-glucan concentrations were detected at 36 °C than those incubated at 28 °C. With the increased temperature, many aberrant chitin deposition patches occurred, and the distribution of chitin in the cell wall was uneven. Moreover, high temperature disrupts the cell wall integrity, and P. ostreatus mycelia became hypersensitive to cell wall-perturbing agents at 36 °C. The cell wall structure tended to shrink or distorted after high temperature. The cell walls were observed to be thicker and looser by using transmission electron microscopy. High temperature can decrease the mannose content in the cell wall and increase the relative cell wall porosity. According to infrared absorption spectrum, high temperature broke or decreased the glycosidic linkages. Finally, P. ostreatus mycelial cell wall was easily degraded by lysing enzymes after high-temperature treatment. In other words, the cell wall destruction caused by high temperature may be a breakthrough for P. ostreatus to be easily infected by Trichoderma.

Antifungal mechanism of sodium dehydroacetate against Geotrichum citri-aurantii.

This study investigated the potential anti-fungal mechanisms of sodium dehydroacetate (SD) against Geotrichum citri-aurantii. The results showed that the cell wall integrity of G. citri-aurantii was not affected, whereas the membrane permeability of G. citri-aurantii mycelia was visibly altered by SD. Dramatic morphological changes of the mycelia, such as loss of cytoplasm, plasmolysis, and dissolution of intracellular substances, were observed by scanning electron microscopy and transmission electron microscopy analyses, indicating that the mycelium is severely damaged by the SD treatment. Furthermore, SD apparently induced a decrease in the intracellular ATP content before 30 min of exposure. An increase in the activity of the Na+/K+-ATPase was also observed, indicating that Na+ ions might enter the cell and thus disturb the energy supply. Taken together, this study's findings suggest that the anti-fungal activity of SD against G. citri-aurantii can be attributed to the disruption of cell membrane permeability and energy metabolism.

Computer-aided diagnosis software for vulvovaginal candidiasis detection from Pap smear images.

Vulvovaginal candidiasis (VVC) is a common gynecologic infection and it occurs when there is overgrowth of the yeast called Candida. VVC diagnosis is usually done by observing a Pap smear sample under a microscope and searching for the conidium and mycelium components of Candida. This manual method is time consuming, subjective and tedious. Any diagnosis tools that detect VVC, semi- or full-automatically, can be very helpful to pathologists. This article presents a computer aided diagnosis (CAD) software to improve human diagnosis of VVC from Pap smear samples. The proposed software is designed based on phenotypic and morphology features of the Candida in Pap smear sample images. This software provide a user-friendly interface which consists of a set of image processing tools and analytical results that helps to detect Candida and determine severity of illness. The software was evaluated on 200 Pap smear sample images and obtained specificity of 91.04% and sensitivity of 92.48% to detect VVC. As a result, the use of the proposed software reduces diagnostic time and can be employed as a second objective opinion for pathologists.

The APSES transcription factor Vst1 is a key regulator of development in microsclerotium- and resting mycelium-producing Verticillium species.

Plant pathogens of the genus Verticillium pose a threat to many important crops worldwide. They are soil-borne fungi which invade the plant systemically, causing wilt symptoms. We functionally characterized the APSES family transcription factor Vst1 in two Verticillium species, V. dahliae and V. nonalfalfae, which produce microsclerotia and melanized hyphae as resistant structures, respectively. We found that, in V. dahliae Δvst1 strains, microsclerotium biogenesis stalled after an initial swelling of hyphal cells and cultures were never pigmented. In V. nonalfalfae Δvst1, melanized hyphae were also absent. These results suggest that Vst1 controls melanin biosynthesis independent of its role in morphogenesis. The absence of vst1 also had a great impact on sporulation in both species, affecting the generation of the characteristic verticillate conidiophore structure and sporulation rates in liquid medium. In contrast with these key roles in development, Vst1 activity was dispensable for virulence. We performed a microarray analysis comparing global transcription patterns of wild-type and Δvst1 in V. dahliae. G-protein/cyclic adenosine monophosphate (G-protein/cAMP) signalling and mitogen-activated protein kinase (MAPK) cascades are known to regulate fungal morphogenesis and virulence. The microarray analysis revealed a negative interaction of Vst1 with G-protein/cAMP signalling and a positive interaction with MAPK signalling. This analysis also identified Rho signalling as a potential regulator of morphogenesis in V. dahliae, positively interacting with Vst1. Furthermore, it exposed the association of secondary metabolism and development in this species, identifying Vst1 as a potential co-regulator of both processes. Characterization of the putative Vst1 targets identified in this study will aid in the dissection of specific aspects of development.

Morphology engineering of Streptomyces coelicolor M145 by sub-inhibitory concentrations of antibiotics.

Growth of Streptomyces in submerged culture is characterized by the formation of complex mycelial particles, known as pellets or clumps, which strongly influence antibiotic production. Also, many bioactive molecules produced by Streptomyces have great potential to modulate soil bacteria morphological development. However, there has been no effort directed at engineering mycelial morphology using these small molecules. Here, thiostrepton was identified, using a combination of qRT-PCR, semi-preparative HPLC, and MALDI-TOF MS, as a pellet-inducing compound produced by S. laurentii ATCC31255. At sub-inhibitory concentration, thiostrepton stimulated Streptomyces coelicolor M145 pellet formation and antibiotics production were altered, with 3-fold and 2-fold decreases in actinorhodin and undecylprodigiosin yields, respectively. It was also shown that mycelial morphology can be influenced by other antibiotic class at sub-inhibitory concentrations. For instance, in the presence of spectinomycin, S. coelicolor M145, which under typical growth conditions forms large diameter pellets with many protruding hyphae, instead formed small diameter pellets with barely visible hyphae at the edge. Importantly, this morphology produced a 4-fold increase in undecylprodigiosin production and 3-fold decrease in actinorhodin production. These results indicated that these small molecules, previously identified as antimicrobials, also have great potential for influencing mycelial morphology.