White Mutant Research Articles

The role of white gene and its mechanism during the formation of curly wing in Drosophila melanogaster.

Curly wing is one of the most frequently used genetic markers in Drosophila melanogaster, but its molecular mechanism is remained unclear. Previous results have showed that physicochemical stimulation would affect the formation of the cruly wing. Our recent study found that H2O2 could not only affect the eclosion rate of D. melanogaster, but also induce the formation of curly wing. Here, we aimed to uncover the specific factors influencing the formation of curly wing in D. melanogaster via changing the concentration of H2O2 and the temperature as well as the time of H2O2 treatment. We measured the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX), in order to examine the effects of H2O2 on antioxidative capacity of D. melanogaster. The results showed that the eclosion rate of D. melanogaster was inversely correlated with the concentration of H2O2. The change of temperature, H2O2 concentration and the period of H2O2 treatment affected the degree of the curl and the proportion of the curly wing. The white mutant flies responded most significantly to these three conditions, the mini-white (white gene reverse mutation) flies could rescue the curly phenotype, and responded similarly to the wild type OR. H2O2 had effects on the formation of the curly wing which contained the Cy mutation, leading to increased rate of the curly wing. D. melanogaster treated with H2O2 would reduce the antioxidative capacity. Results from real-time quantitative PCR showed that H2O2 treatment resulted in a change in gene expression. The formation of curly wing was a complicated process, and H2O2 might act as a signaling molecule or indirectly affect certain factors in the formation of curly wing in D. melano-gaster. This process might share the same signaling pathway with the Cy mutant, or might be regulated by different modulating patterns.

Partial secretome analysis of Caldariomyces fumago reveals extracellular production of the CPO co-substrate H2O2 and provides a coproduction concept for CPO and glucose oxidase.

The culture supernatant of Caldariomyces fumago strains grown in a minimal medium with fructose contains mainly the biotechnologically relevant enzyme chloroperoxidase (CPO) and only minor amounts of other proteins. Our approach to identify the nature of these proteins via peptide mass fingerprinting and transcriptome analysis demonstrated the presence of putative glycosyl hydrolase and glucose oxidase (GOx) enzymes. These activities had been described earlier as parts of the fungus´ halogenation machinery, as they provide CPO with the co-substrate H2O2. The GOx activity was found to have a pH optimum of 5. Compared to the wild type values, GOx activity and glucose-driven MCD chlorination activity in the culture of a white mutant were found to be strongly increased to values of 1-2UmL-1. As most CPO-catalyzed peroxidation reactions also show pH optima at around 5, the C. fumago culture supernatant can provide a highly convenient CPO/GOx source for many reactions with in situ H2O2 production.

Drosophila melanogaster White Mutant w1118 Undergo Retinal Degeneration.

Key scientific discoveries have resulted from genetic studies of Drosophila melanogaster, using a multitude of transgenic fly strains, the majority of which are constructed in a genetic background containing mutations in the white gene. Here we report that white mutant flies from w1118 strain undergo retinal degeneration. We observed also that w1118 mutants have progressive loss of climbing ability, shortened life span, as well as impaired resistance to various forms of stress. Retinal degeneration was abolished by transgenic expression of mini-white+ in the white null background w1118. We conclude that beyond the classical eye-color phenotype, mutations in Drosophila white gene could impair several biological functions affecting parameters like mobility, life span and stress tolerance. Consequently, we suggest caution and attentiveness during the interpretation of old experiments employing white mutant flies and when planning new ones, especially within the research field of neurodegeneration and neuroprotection. We also encourage that the use of w1118 strain as a wild-type control should be avoided.

Transcriptome analysis reveals potential genes involved in flower pigmentation in a red-flowered mutant of white clover (Trifolium repens L.)

White clover (Trifolium repens L.) has been cultivated for ornamental use because of its flowers, leaf marks and creeping habit. Although a mutation in flower color is very infrequent in this species, the red-flowered mutant of white clover was a novel germplasm for ornamental white clover breeding. The mechanism of flower pigmentation in white clover is still limited because of the rarity of mutation materials and the lack of genomic data. In this study, two cDNA libraries from red-flowered white clover mutant between sunlight-exposed plants and shade-treated plants, respectively, were used for transcriptome sequencing. A total of 157,964 unigenes with an average length of 728bp and a median length of 1346bp were isolated. A large number of differentially expressed genes (6282) that were potentially involved in multiple biological and metabolic pathways, including anthocyanin flavonoid biosynthetic pathway and flavonoid biosynthetic pathway, were obtained, 70 of which could be identified as putative homologues of color-related genes. Furthermore, eight key candidate genes (CHS, F3′H, F3′5′H, UFGT, FLS, LAR, ANS, and DFR) in flavonoid biological synthesis pathway were identified by quantitative real-time PCR (qRT-PCR). Mass sequence data obtained by RNA-Seq of white clover and its red-flowered mutant provided basic sequence information and a platform for future molecular biological research on the red flower trait.

Identification of Light-Independent Anthocyanin Biosynthesis Mutants Induced by Ethyl Methane Sulfonate in Turnip "Tsuda" (Brassica rapa).

The epidermis of swollen storage roots in purple cultivars of turnip “Tsuda” (Brassica rapa) accumulates anthocyanin in a light-dependent manner, especially in response to UV-A light, of which the mechanism is unclear. In this study, we mutagenized 15,000 seeds by 0.5% (v/v) ethyl methane sulfonate (EMS) and obtained 14 mutants with abnormal anthocyanin production in their epidermis of swollen storage roots. These mutants were classified into two groups: the red mutants with constitutive anthocyanin accumulation in their epidermis of storage roots even in underground parts in darkness and the white mutants without anthocyanin accumulation in the epidermis of storage roots in aboveground parts exposed to sunlight. Test cross analysis demonstrated that w9, w68, w204, r15, r21, r30 and r57 contained different mutations responsible for their phenotypic variations. Further genetic analysis of four target mutants (w9, w68, w204 and r15) indicated that each of them was controlled by a different recessive gene. Intriguingly, the expression profiles of anthocyanin biosynthesis genes, including structural and regulatory genes, coincided with their anthocyanin levels in the epidermis of storage roots in the four target mutants. We proposed that potential genes responsible for the mutations should be upstream factors of the anthocyanin biosynthesis pathway in turnips, which provided resources to further investigate the mechanisms of light-induced anthocyanin accumulation.

Circadian Expression of PERIOD and the Pigment-Dispersing Factor in the yellow white mutant Drosophila melanogaster

Daily behavioral andphysiological rhythms in most animals are regulated by a circadian clock. Inthe fruit fly, Drosophila melanogaster, this clock consists of a networkof about 150 cerebral neurons. Different parameters of the fruit fly circadianlocomotion are attributed to specific neuronal subsets and the molecularrhythms of clock genes and proteins within them. To understand the clockmachinery, many clock mutant flies have been used. yellow white (y w) mutation in D. melanogaster cause impairedmelanisation, eye pigmentation loss, and behavioral alterations includingchanges in circadian locomotion. This study investigates the possible molecularbackground for these circadian alterations. Results revealed that in the outputpathway of the clock, the Pigment-Dispersing Factor (PDF) expression wassuppressed in y w mutant fruit flies compared to Canton S (CS) wild-type in the PDF+ clock neurons. Onthe other hand, the degradation of the PERIOD (PER) protein was significantlydelayed in yw mutants and their levels was higher, especially atthe transition from dark to light. The combined effect of elevated PER levelsand suppressed PDF signaling provides an explanation for the delayed morninglocomotor activity peak (M) and advanced evening peak (E) of y w fliescompared to CS.It could be concluded that mutations affecting eye pigmentation like the y w mutationcould have profound effects on the circadian regulation of behavior and theirunderlying molecular oscillations in clock neurons. These effects reduce theplasticity and robustness of the circadian clock and expose the flies to higherlevels of the environmental risk of desiccation.

Establishment of CRISPR/Cas9 in Alternaria alternata

The filamentous fungus Alternaria alternata is a potent producer of many secondary metabolites, some of which like alternariol or alternariol-methyl ether are toxic and/or cancerogenic. Many Alternaria species do not only cause post-harvest losses of food and feed, but are aggressive plant pathogens. Despite the great economic importance and the large number of research groups working with the fungus, the molecular toolbox is rather underdeveloped. Gene deletions often result in heterokaryotic strains and therefore, gene-function analyses are rather tedious. In addition, A. alternata lacks a sexual cycle and classical genetic approaches cannot be combined with molecular biological methods. Here, we show that CRISPR/Cas9 can be efficiently used for gene inactivation. Two genes of the melanin biosynthesis pathway, pksA and brm2, were chosen as targets. Several white mutants were obtained after several rounds of strain purification through protoplast regeneration or spore inoculation. Mutation of the genes was due to deletions from 1bp to 1.5kbp. The CRISPR/Cas9 system was also used to inactivate the orotidine-5-phosphate decarboxylase gene pyrG to create a uracil-auxotrophic strain. The strain was counter-selected with fluor-orotic acid and could be re-transformed with pyrG from Aspergillus fumigatus and pyr-4 from Neurospora crassa. In order to test the functioning of GFP, the fluorescent protein was fused to a nuclear localization signal derived from the StuA transcription factor of Aspergillus nidulans. After transformation bright nuclei were visible.

Changes in Anthocyanin Production during Domestication of Citrus.

Mandarin (Citrus reticulata), citron (Citrus medica), and pummelo (Citrus maxima) are important species of the genus Citrus and parents of the interspecific hybrids that constitute the most familiar commercial varieties of Citrus: sweet orange, sour orange, clementine, lemon, lime, and grapefruit. Citron produces anthocyanins in its young leaves and flowers, as do species in genera closely related to Citrus, but mandarins do not, and pummelo varieties that produce anthocyanins have not been reported. We investigated the activity of the Ruby gene, which encodes a MYB transcription factor controlling anthocyanin biosynthesis, in different accessions of a range of Citrus species and in domesticated cultivars. A white mutant of lemon lacks functional alleles of Ruby, demonstrating that Ruby plays an essential role in anthocyanin production in Citrus Almost all the natural variation in pigmentation by anthocyanins in Citrus species can be explained by differences in activity of the Ruby gene, caused by point mutations and deletions and insertions of transposable elements. Comparison of the allelic constitution of Ruby in different species and cultivars also helps to clarify many of the taxonomic relationships in different species of Citrus, confirms the derivation of commercial varieties during domestication, elucidates the relationships within the subgenus Papeda, and allows a new genetic classification of mandarins.

Identification of Mutant Genes and Introgressed Tiger Salamander DNA in the Laboratory Axolotl, Ambystoma mexicanum

The molecular genetic toolkit of the Mexican axolotl, a classic model organism, has matured to the point where it is now possible to identify genes for mutant phenotypes. We used a positional cloning–candidate gene approach to identify molecular bases for two historic axolotl pigment phenotypes: white and albino. White (d/d) mutants have defects in pigment cell morphogenesis and differentiation, whereas albino (a/a) mutants lack melanin. We identified in white mutants a transcriptional defect in endothelin 3 (edn3), encoding a peptide factor that promotes pigment cell migration and differentiation in other vertebrates. Transgenic restoration of Edn3 expression rescued the homozygous white mutant phenotype. We mapped the albino locus to tyrosinase (tyr) and identified polymorphisms shared between the albino allele (tyra) and tyr alleles in a Minnesota population of tiger salamanders from which the albino trait was introgressed. tyra has a 142 bp deletion and similar engineered alleles recapitulated the albino phenotype. Finally, we show that historical introgression of tyra significantly altered genomic composition of the laboratory axolotl, yielding a distinct, hybrid strain of ambystomatid salamander. Our results demonstrate the feasibility of identifying genes for traits in the laboratory Mexican axolotl.

Different age-dependent performance in Drosophila wild-type Canton-S and the white mutant w1118 flies

Aging has significant effects on the locomotor performance of insects including Drosophila. Using a protocol for the high-throughput analysis of fly locomotion in a circular arena, we examined age-dependent behavioral characteristics in adult flies. There are widely used wild-type and genetically engineered background lines including the Canton-S strain and the w1118 strain, which has a null mutation of the white gene. Under standard rearing conditions, we found similar survival and median lifespans in Canton-S (50days) and w1118 (54days) strains, however, w1118 flies maintained stable body mass for up to 43days, whereas Canton-S flies gained body mass at young age, followed by a gradual decline. We also tested the behavioral performance of young and old flies. Compared with young w1118 flies (5–10days), old w1118 flies (40–45days) had an increased boundary preference during locomotion in small circular arenas, and increased speed of locomotor recovery from anoxia. Old Canton-S files, however, exhibited unchanged boundary preference and reduced recovery speed from anoxia relative to young flies. In addition, old w1118 flies showed decreased path length per minute and reduced 0.2s path increment compared with young flies, whereas old Canton-S flies displayed the same path length per minute and the same 0.2s path increment compared with young flies. We conclude that age-dependent behavioral and physiological changes differ between Canton-S and w1118 flies. These results illustrate that phenotypic differences between strains can change qualitatively, as well as quantitatively, as the animals age.

Comparison of Treatment Strategies in Patients over 60 Years with AML: Final Analysis of a Prospective Randomized German AML Intergroup Study

Comparison of Treatment Strategies in Patients over 60 Years with AML: Final Analysis of a Prospective Randomized German AML Intergroup Study

Phosphorylation of GENOMES UNCOUPLED 4 Alters Stimulation of Mg Chelatase Activity in Angiosperms.

GENOMES UNCOUPLED 4 (GUN4) is a positive regulator of light-dependent chlorophyll biosynthesis. GUN4 activates Mg chelatase (MgCh) that catalyzes the insertion of an Mg2+ ion into protoporphyrin IX. We show that Arabidopsis (Arabidopsis thaliana) GUN4 is phosphorylated at Ser 264 (S264), the penultimate amino acid residue at the C terminus. While GUN4 is preferentially phosphorylated in darkness, phosphorylation is reduced upon accumulation of Mg porphyrins. Expression of a phosphomimicking GUN4(S264D) results in an incomplete complementation of the white gun4-2 null mutant and a chlorotic phenotype comparable to gun4 knockdown mutants. Phosphorylated GUN4 has a reduced stimulatory effect on MgCh in vitro and in vivo but retains its protein stability and tetrapyrrole binding capacity. Analysis of GUN4 found in oxygenic photosynthetic organisms reveals the evolution of a C-terminal extension, which harbors the phosphorylation site of GUN4 expressed in angiosperms. Homologs of GUN4 from Synechocystis and Chlamydomonas lack the conserved phosphorylation site found in a C-terminal extension of angiosperm GUN4. Biochemical studies proved the importance of the C-terminal extension for MgCh stimulation and inactivation of GUN4 by phosphorylation in angiosperms. An additional mechanism regulating MgCh activity is proposed. In conjunction with the dark repression of 5-aminolevulinic acid synthesis, GUN4 phosphorylation minimizes the flow of intermediates into the Mg branch of the tetrapyrrole metabolic pathway for chlorophyll biosynthesis.

Cyclofarnesoids and methylhexanoids produced from β-carotene in Phycomyces blakesleeanus

The oxidative cleavage of β-carotene in the Mucorales produces three fragments of 18, 15, and 7 carbons, respective heads of three families of apocarotenoids: the methylhexanoids, the trisporoids, and the cyclofarnesoids (named after their 1,6-cyclofarnesane skeleton). The apocarotenoids are easily recognized because they are absent in white mutants unable to produce β-carotene. In cultures of Phycomyces blakesleeanus we detected thirty-two apocarotenoids by LC, UV absorbance, and MS. With additional IR and NMR we identified two methylhexanoids and the eight most abundant cyclofarnesoids. Four of them were previously-unknown natural compounds, including 4-dihydrocyclofarnesine S, the most abundant cyclofarnesoid in young cultures. We arranged the apocarotenoids of the Mucorales in a scheme that helps classifying and naming them and suggests possible metabolites and biosynthetic pathways. We propose specific biosynthetic pathways for cyclofarnesoids and methylhexanoids based on structural comparisons, the time course of appearance of individual compounds, and the bioconversion of β-apo-12-carotenol, an early precursor, to three more oxygenated cyclofarnesoids by the white mutants. Some of the reactions occur spontaneously in the increasingly acidic culture media. Mating increased the contents of methylhexanoids and cyclofarnesoids by ca. threefold in young cultures and ca. twelvefold in old ones (five days); cyclofarnesine S, the most abundant cyclofarnesoid in old cultures, increased over one hundredfold. We found no differences between the sexes and no activity as sexual pheromones, but we suggest that methylhexanoids and cyclofarnesoids could mediate species-specific physiology and behavior.

Enhancement of yellow pigment production by intraspecific protoplast fusion of Monascus spp. yellow mutant (ade−) and white mutant (prototroph)

To breed industrially useful strains of a slow-growing, yellow pigment producing strain of Monascus sp., protoplasts of Monascus purpureus yellow mutant (ade−) and rapid-growing M. purpureus white mutant (prototroph) were fused and fusants were selected on minimal medium (MM). Preliminary conventional protoplast fusion of the two strains was performed and the result showed that only white colonies were detected on MM. It was not able to differentiate the fusants from the white parental prototroph. To solve this problem, the white parental prototroph was thus pretreated with 20mM iodoacetamide (IOA) for cytoplasm inactivation and subsequently taken into protoplast fusion with slow-growing Monascus yellow mutant. Under this development technique, only the fusants, with viable cytoplasm from Monascus yellow mutant (ade−), could thus grow on MM, whereas neither IOA pretreated white parental prototroph nor yellow auxotroph (ade−) could survive. Fifty-three fusants isolated from yellow colonies obtained through this developed technique were subsequently inoculated on complete medium (MY agar). Fifteen distinguished yellow colonies from their parental yellow mutant were then selected for biochemical, morphological and fermentative properties in cassava starch and soybean flour (SS) broth. Finally, three most stable fusants (F7, F10 and F43) were then selected and compared in rice solid culture. Enhancement of yellow pigment production over the parental yellow auxotroph was found in F7 and F10, while enhanced glucoamylase activity was found in F43. The formation of fusants was further confirmed by monacolin K content, which was intermediate between the two parents (monacolin K-producing yellow auxotroph and non-monacolin K producing white prototroph).

WHITISH-FLESH COLOR MUTATION IN LOQUAT INVOLVES FRUCTOSE BIOSYNTHESIS AND S-LOCUS

Loquat (Eriobotrya japonica Lindl.) produces yellowish-flesh and whitish-flesh fruits. A bud mutation with whitish-flesh fruits originating from the yellowish-flesh cultivar ‘Dongting’ was discovered. The white mutant and yellow loquats were collected and used in this study. Two polymorphic bands were obtained with the primers UBC813/535 and OPH01/1719, discriminating between wild and mutant genomes. The deduced amino acids of the two sequences were highly correlated with NAD-dependent sorbitol dehydrogenase (NAD+-SDH) in E. japonica and F-box proteins, S ribonuclease (S-RNase) in P. pyrifolia. Three SNP variances at nucleotide 32, 370 and 461 in the coding sequence of the NAD-SDH gene, were observed in whitish fruit mutants, and the amino acids of the three alleles were also different. In addition, real-time quantitative PCR showed that NAD-SDH and some other carotenogenic genes were considerably suppressed in ripe mutant fruits compared to those in wild fruits. These results suggest that flesh color of loquat might be controlled by at least two loci referring to NAD+-SDH and S-locus, in addition to expression levels of carotenogenic genes. The NAD-SDH might be an upstream gene involved in I²-carotene accumulation in yellowish-flesh fruit and it may be important for flesh color and fructose biosynthesis.

Metabolic and molecular analyses of white mutant Vaccinium berries show down-regulation of MYBPA1-type R2R3 MYB regulatory factor.

MYBPA1-type R2R3 MYB transcription factor shows down-regulation in white mutant berries of Vaccinium uliginosum deficient in anthocyanins but not proanthocyanidins suggesting a role in the regulation of anthocyanin biosynthesis. Berries of the genus Vaccinium are among the best natural sources of flavonoids. In this study, the expression of structural and regulatory flavonoid biosynthetic genes and the accumulation of flavonoids in white mutant and blue-colored wild-type bog bilberry (V. uliginosum) fruits were measured at different stages of berry development. In contrast to high contents of anthocyanins in ripe blue-colored berries, only traces were detected by HPLC-ESI-MS in ripe white mutant berries. However, similar profile and high levels of flavonol glycosides and proanthocyanidins were quantified in both ripe white and ripe wild-type berries. Analysis with qRT-PCR showed strong down-regulation of structural genes chalcone synthase (VuCHS), dihydroflavonol 4-reductase (VuDFR) and anthocyanidin synthase (VuANS) as well as MYBPA1-type transcription factor VuMYBPA1 in white berries during ripening compared to wild-type berries. The profiles of transcript accumulation of chalcone isomerase (VuCHI), anthocyanidin reductase (VuANR), leucoanthocyanidin reductase (VuLAR) and flavonoid 3'5' hydroxylase (VuF3'5'H) were more similar between the white and the wild-type berries during fruit development, while expression of UDP-glucose: flavonoid 3-O-glucosyltransferase (VuUFGT) showed similar trend but fourfold lower level in white mutant. VuMYBPA1, the R2R3 MYB family member, is a homologue of VmMYB2 of V. myrtillus and VcMYBPA1 of V. corymbosum and belongs to MYBPA1-type MYB family which members are shown in some species to be related with proanthocyanidin biosynthesis in fruits. Our results combined with earlier data of the role of VmMYB2 in white mutant berries of V. myrtillus suggest that the regulation of anthocyanin biosynthesis in Vaccinium species could differ from other species studied.

Characterization of oxidative phosphorylation enzymes in Euglena gracilis and its white mutant strain WgmZOflL

The enzymes involved in Euglena oxidative phosphorylation (OXPHOS) were characterized in this study. We have demonstrated that Euglena gracilis strain Z and its stable bleached non-photosynthetic mutant strain WgmZOflL both possess fully functional OXPHOS apparatus as well as pathways requiring terminal alternative oxidase(s) and alternative mitochondrial NADH-dehydrogenase(s). Light (or dark) and plastid (non)functionality seem to have little effect on oxygen consumption, the activities of the enzymes involved in OXPHOS and the action of respiration inhibitors in Euglena. This study also demonstrates biochemical properties of complex III (cytochrome c reductase) in Euglena.

Identification and Gene Fine Mapping of White Panicle Mutant wp4 in Oryza sativa

Identification and Gene Fine Mapping of White Panicle Mutant <i>wp4</i> in <i>Oryza sativa</i>

Photosynthetic Characteristics of Flag Leaves in Rice White Stripe Mutant 6001 During Senescence Process

Physiological, biochemical and electron microscopy analyses were used to investigate the photosynthetic performance of flag leaves in rice white stripe mutant 6001 during the senescence process. Results showed that the chlorophyll content at the heading and milk-ripe stages in rice mutant 6001 were about 34.78% and 3.00% less than those in wild type 6028, respectively. However, the chlorophyll content at the fully-ripe stage in rice mutant 6001 was higher than that in wild type 6028. At the heading stage, the net photosynthetic rate (Pn) in rice mutant 6001 was lower than that in wild type 6028. Rice mutant 6001 also exhibited a significantly slower decrease rate of Pn than wild type 6028 during the senescence progress, especially at the later stage. Furthermore, Ca2+-ATPase, Mg2+-ATPase and photophosphorylation activities exhibited the similar trends as the Pn. During the senescence process, the 68 kDa polypeptide concentrations in the thylakoid membrane proteins exhibited a significant change, which was one of the critical factors that contributed to the observed change in photosynthesis. We also observed that the chloroplasts of rice mutant 6001 exhibited higher integrity than those of wild type 6028, and the chloroplast membrane of rice mutant 6001 disintegrated more slow during the senescence process. In general, rice mutant 6001 had a relatively slower senescence rate than wild type 6028, and exhibited anti-senescence properties.

Biofilm formation is not a prerequisite for production of the antibacterial compound tropodithietic acid inPhaeobacter inhibensDSM17395

The goal of this study was to investigate if biofilm formation on population level is a physiological requirement for antagonism in Phaeobacter inhibens DSM17395, since the antibiotic compound tropodithietic acid (TDA) is produced by several Roseobacter clade species during growth as multicellular aggregates or biofilms at the air-liquid interface and is induced on single cell level upon attachment. A mutant library was created by Tn5 transposon insertion and 22 TDA-positive (brown) mutants with decreased biofilm formation or adhesion, and eight TDA-negative (white) mutants with increased biofilm formation or adhesion were selected. None of the selected biofilm-overproducing white mutants showed any antibiotic activity, while all brown mutants with reduced or disabled biofilm formation produced the antibacterial compound. Sequencing analysis indicated that genes that are likely involved in EPS/LPS production, motility and chemotaxis, and redox regulation play a role in biofilm formation and/or adhesion in P.inhibens DSM17395. Cell aggregation and biofilm formation are not physiological prerequisites for TDA production. This study contributes to the understanding of TDA production in P.inhibens, which has great potential as a probiotic in marine larviculture.