Characterization and applications of MSS pigment isolated from Streptomyces ardesiacus.

The textile industry is one of the largest worldwide polluters of clean water due to the heavy use of synthetic dyes. These chemicals negatively affect the environment, especially aquatic life due to their toxic and mutagenic properties. Synthetic dyes cause harm to human health such as skin allergies and respiratory sensitization. Several advantages such as ease of extraction, availability, high yields and no seasonal variation make microbial pigments the most ideal source of natural pigments. This study was done to isolate colour pigment producing bacteria and fungi from soil collected from organic farms from various locations in Sri Lanka. Out of 7 soil samples, 3 yielded pigment producing bacteria and fungi. In total, 9 pigment producing bacteria and 3 pigment producing fungi were isolated. Gause’s synthetic agar yielded the most pigmented isolates. Isolates were inoculated in broths and pigment production was observed. Extracellular pigments produced by 5 of the bacterial isolates were extracted by a water-based method. The antibacterial activity of the pigments in their crude and concentrated forms was tested using the well diffusion method against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P. Inhibition zone against S. aureus was observed for both crude (12.33±0.58mm) and concentrated pigments (9.67±0.58mm) extracted from purple pigment producing bacterial isolate (BPU). This pigment has the potential to be used in antibacterial textile preparation. Extracted pigments were used to dye scoured cotton fabric with the use of 3% alum as mordant. Pigment from BPU isolate resulted in better coloured fabric.

The textile industry is one of the largest worldwide polluters of clean water due to the heavy use of synthetic dyes. Synthetic dyes are harmful to aquatic life and to human health. To overcome this, natural dyes are being explored as a healthier and more eco-friendly alternative. Several advantages such as ease of extraction, availability, high yields and no seasonal variation make microbial pigments the most ideal source of natural pigments. This study was done to isolate colour pigment producing bacteria and fungi from soil collected from organic farms from various locations in Sri Lanka. In total, 9 pigment producing bacteria and 3 pigment producing fungi were isolated. Gause’s synthetic agar yielded the most pigmented isolates. Extracellular pigments produced by 5 of the bacterial isolates were extracted by a water based method. The antibacterial activity of the pigments in their crude and concentrated forms was tested using the well diffusion method against E.coli ATCC 8739 and Staphylococcus aureus ATCC 6538P. Inhibition zone against S.aureus was observed for both crude (12.33±0.58mm) and concentrated pigments (9.67±0.58mm) extracted from purple pigment producing bacterial isolate (BPU). This pigment has the potential to be used in antibacterial textile preparation. Extracted pigments were used to dye scoured cotton fabric with the use of 3% alum as mordant. Pigment from BPU isolate resulted in better coloured fabric.

To investigate the characteristics of growth and metabolism and the in vivo toxicity of Candida auris under different conditions. We observed the growth of Candida auris and Candida albicans under routine culture conditions and in different pH and salt concentrations, and compared their activities of sugar fermentation using microbiochemical reaction tubes. Four-week-old nude mice were randomized into Candida auris infection group (n=5), Candida albicans infection group (n=5) and control group (n=5) for intragastric administration of 0.3 mL suspension the two Candida species (5×109 cfu/mL) or 0.3 mL normal saline. Samples of the liver, kidney, intestine, feces and blood were taken for analysis of the in vivo distribution and toxicity of Candida albicans by fungal culture and histopathological examination. Candida auris exhibited logarithmic growth at 8-24 h after inoculation and showed stable growth after 24 h. Candida auris showed optimal growth within the pH value range of 5-7 with a growth pattern identical to that of Candida albicans. Candida auris grew better than Candida albicans in media containing 5% and 10% NaCl, and could ferment glucose, sucrose, trehalose and sorbitol. Candida auris could be isolated from the feces, blood, liver and kidney of infected nude mice, and the liver had the highest fungal load (5.7 log10 cfu/g). Candida auris could cause pathological changes in the liver and intestine of the mice, but with a lesser severity as compared with Candida albicans. Candida auris exhibits optimal growth in mildly acidic or neutral conditions with a high salt tolerance, and can potentially penetrate the intestinal barrier into blood and lead to tissue injuries in hosts with immunosuppression.

Textile materials (natural and synthetic) used to be coloured for value addition, look and desire of the customers. Anciently, this purpose of colouring textile was initiated using colours of natural source, untill synthetic colours/dyes were invented and commercialized. For ready availability of pure synthetic dyes of different types/classes and its cost advantages, most of textile dyers/ manufacturers shifted towards use of synthetic colourant. Almost all the synthetic colourants being synthesized from petrochemical sources through hazardous chemical processes poses threat towards its eco-friendliness. Hence, worldwide, growing consciousness about organic value of eco-friendly products has generated renewed interest of consumers towards use of textiles (preferably natural fibre product) dyed with eco-friendly natural dyes. Natural dyes are known for their use in colouring of food substrate, leather as well as natural fibres like wool, silk and cotton as major areas of application since pre-historic times. Although this ancient art of dyeing textiles with natural dyes withstood the ravages of time, but due to the wide availability of synthetic dyes at an economical price, a rapid decline in natural dyeing continued. However, even after a century, the uses of natural dyes never erode completely and they are being still used in different places of the world. Thus, natural dyeing of different textiles and leathers has been continued mainly in the decentralized sector for specialty products besides the use of synthetic dyes in the large scale sector for general textiles/apparels. Recently, most of the commercial dyers and textile export houses have started re-looking to the maximum possibilities of using natural dyes for dyeing and printing of different textiles for targeting niche market. Natural dyes produce very uncommon, soothing and soft shades as compared to synthetic dyes. On the other hand, synthetic dyes, which are widely available at an economical price and produce a wide variety of colours, sometimes causes skin allergy and other harmfulness to human body, produces toxicity/chemical hazards during its synthesis, releases undesirable/hazardous/toxic chemicals etc. For successful commercial use of natural dyes for any particular fibres, the appropriate and standardized techniques for dyeing for that particular fibre-natural dye system need to be adopted. Therefore to obtain newer shade with acceptable colour fastness behaviour and reproducible colour yield, appropriate scientific dyeing techniques/procedures are to be derived. Thus, relevant scientific studies and its output on standardization of dyeing

Background and introduction: Bloodstream Candida infection, or candidemia, is a serious fungal infection caused by Candida species, often occurring in hospitalized or immunocompromised patients. It can lead to severe complications, including sepsis and multi-organ failure. The emergence of antifungal resistance, particularly in species like Candida auris and Candida glabrata, poses a significant challenge to treatment.Material and methods: This was a hospital-based retrospective study conducted over a five-year period, from January 2020 to December 2024. All bloodstream infection clinical sample details were collected from the microbiology laboratory with Candida infection. A total of 1058 isolates of Candida species were included in the study. The study samples were the clinically relevant Candida isolates for which antifungal susceptibility testing was done at a tertiary care hospital in North India. The data were entered into a database, and an antibiogram for Candida species was generated. Results: Candida tropicalis was the most prevalent, with 340 isolates, which make up 32.13% of the total isolates of Candida. Candida parapsilosis was the next most common, with 145 isolates, comprising 13.7% of the total isolates. Candida auris accounted for 100 isolates, representing 9.45% of the total isolates. Candida albicans, the fourth most common Candida genus, was 96 isolates (9.07%), making it less common in comparison to Candida non-albicans. Isolates from paediatric patients dominate the list, with significantly higher samples compared to the others, followed by adult patients from medicine departments with 218 samples, showing its importance in overall sample contributions. Among antifungals, caspofungin had the highest sensitivity across most species, e.g., Candida albicans at 94.7%, Candida parapsilosis at 98.6%, and Candida tropicalis at 97.5%. Caspofungin was found to be 96% sensitive to Candida auris. Fluconazole displays variable effectiveness as low susceptibility was found in Candida auris (8.9%) and Candida glabrata (35.1%). Voriconazole maintains relatively high susceptibility, with better performance compared to fluconazole in most species, e.g., Candida albicans (84%) and Candida glabrata (78.9%).Conclusion: Candida tropicalis emerged as the most prevalent species, followed by Candida parapsilosis, Candida auris, and Candida albicans, with non-albicans species being more common overall. Candida resistance is a growing clinical challenge that requires urgent attention.At one time, Candida albicans was the most common organism; however, Candida auris has now emerged as the most common resistant pathogen in hospitals across India, with its resistance continuing to increase.

It is known that the corneal epithelium strongly absorbs ultraviolet radiation (UVR). The aim of the present study was to examine the protective role of corneal epithelium against UVR damage by comparing the biological effect of UVR exposure on whole corneas with that on de-epithelialized corneas. Six New Zealand albino rabbit corneas were exposed to UVR centred around 280 nm at a dose that causes biomicroscopically significant keratitis (012 J/cm(2)). Three corneas underwent manual de-epithelialization prior to UVR exposure. A control group of three rabbits underwent only manual de-epithelialization. The animals were killed 76 hours after treatment. The corneas were stained with haematoxylin and evaluated by light microscopy. Corneas that underwent only the exposure to UVR showed a loss of epithelial cells in the treated area. No damage to keratocytes or the stroma was detected. Corneas that underwent manual de-epithelialization showed a loss of epithelial cells, and also keratocytes in the anterior quarter of the corneal stroma. However, corneas that were exposed to UVR after manual de-epithelialization showed very deep stromal damage. The keratocytes disappeared through the entire thickness of the stroma in the UVR-exposed area. Exposure to UVR at 280 nm alone does not result in any deep damage to the corneal stroma and keratocytes. Manual de-epithelialization causes the disappearance of anterior keratocytes. However, the stromal damage caused by UVR in the de-epithelialized corneas was very deep. The corneal epithelium serves to protect the deeper corneal structures against UVR damage, probably by absorbing a substantial amount of the UVR energy applied to the eye.

Synthetic dyes and colourants have been the mainstay of the pigment industry for decades. Researchers are eager to find a more environment friendly and non-toxic substitute because these synthetic dyes have a negative impact on the environment and people's health. Microbial pigments might be an alternative to synthetic pigments. Microbial pigments are categorized as secondary metabolites and are mainly produced due to impaired metabolism under stressful conditions. These pigments have vibrant shades and possess nutritional and therapeutic properties compared to synthetic pigment. Microbial pigments are now widely used within the pharmaceuticals, food, paints, and textile industries. The pharmaceutical industries currently use bacterial pigments as a medicine alternative for cancer and many other bacterial infections. Their growing popularity is a result of their low cost, biodegradable, non-carcinogenic, and environmentally beneficial attributes. This audit article has made an effort to take an in-depth look into the existing uses of bacterial pigments in the food and pharmaceutical industries and project their potential future applications.

Chapter 11 - Harmful environmental effects for textile chemical dyeing practice

The textile industry is considered the second most polluting industry in the world. Synthetic nonbiodegradable petroleum-based dyes and toxic mordants play a major part in this pollution. Almost 20% of global water pollution has been associated with the textile dyeing practices. These controversies with the current environmental regulations, lead to a great demand for natural colors in food, pharmaceuticals, cosmetics, textiles and in the printing dye industry. Recently, microbial pigments have been shown to be a promising alternative not only to synthetic dyes, but also to other biopigments derived from vegetables or animals as they are viewed as natural, non-toxic, have no seasonal production issues, offer excellent productivity, economical and most important they are ecofriendly. An environmental screening of 77 samples was carried out for pigment production. Pigmented bacteria represented 55 (68%) of total samples with the highest percentage of pigmented bacteria found in air samples and the lowest percentage from water samples. Five potential pigmented isolates were chosen for pigment extraction and used for dyeing three types of fabrics - nylon, wool, and polyester. Furthermore, stability of dyes following treatment with acid, alkaline and detergents was studied to investigate the retention of dyes. Bacterial pigments in some unmordanted fabrics were retained 100% in cases of acid treatments while a small amount of discoloration was observed when subjected to alkali, or cold water and detergent. Apart from colorant, Serratia marcescens pigments demonstrated antibacterial activity against gram positive bacteria. The current study demonstrated that coloring ability of the natural dyes can be compared to that of the synthetic dyes. Furthermore, these biochromes are also able to produce various shades similar to those of the synthetic dyes and express variable resistance to treatment with acid, alkaline and detergents.

Natural dye extracted from Caesalpinia sappan Linn. was applied to a cotton fabric and silk yarn by dyeing process. The dyestuff component of Caesalpinia sappan Linn. was extracted using water and ethanol. Analytical studies such as UV–VIS spectrophotometry and gravimetric analysis were performed on the extracts. Brazilein, the major dyestuff component of Caesalpinia sappan Linn. was confirmed in both aqueous and ethanolic extracts by UV–VIS spectrum. The color of each dyed material was investigated in terms of the CIELAB (L*, a* and b*) and K/S values. Cotton fabric dyed without mordant had a shade of reddish-brown, while those post-mordanted with aluminum potassium sulfate, ferrous sulfate and copper sulfate produced a variety of wine red to dark purple color shades. Cotton fabric and silk yarn dyeing was studied using aluminum potassium sulfate as a mordant. The observed color strength was enhanced with increase in mordant concentration.

Clean dyeing of acrylic fabric by sustainable red bacterial pigment based on nano-suspension system

Microbial pigments, regarded as the most potential biomass pigments, have lately attracted increasing attention in textile dyeing due to their sustainability and cleaner production. The pyrrole structure microbial pigment, called prodigiosin, recently have become a research hotspot for its bright colors and antibacterial function. However, in most case the extraction and preparation are time-consuming and expensive processes since these kinds of microbial pigments are intracellular metabolites. In order to promote the application of microbial pigments in textile dyeing, a novel idea of preparing dye liquid of pyrrole structure pigments based on fermentation broth was put forward via increasing the proportion of extracellular pigments. A model membrane platform was established with a planar lipid bilayer to investigate transmembrane transport of microbial pigments and permeability barrier of cell membrane. The nano-dispersion of pigments was produced as the dye liquor owing to high-throughput transmembrane transfer of intracellular pigments and the increase of extracellular pigments proportion. The results indicated that the size and surface electrical properties of the pigments had contributed much to the mass transfer. It is also showed that transmembrane transmission of the intracellular pigments could be regulated by physical and chemical methods. With the improvement of transmembrane transfer efficiency of microbial pigments and the proportion of extracellular pigments, the complicated biological separation process could be avoided and the application of microbial pigments in textile dyeing can be promoted.

The effect of pH on bioremediation potential for the removal of direct violet textile dye by Aspergillus niger

BackgroundYet often overlooked in public health discourse, fungal infections pose a crucial global disease burden associated with annual mortality rates approximately equal to tuberculosis and HIV. In response, the WHO published its first global priority list of fungal pathogens in 2022 assigning Aspergillus fumigatus, Candida albicans, Candida auris, and Cryptococcus neoformans to the critical group. ObjectivesThis review provides succinct insights into novel antifungals in development, aiming to contribute valuable information and perspectives with a focus on recent clinical findings and new treatment approaches for critical members of the WHO fungal pathogen priority list. SourcesPubMed literature search using ‘Aspergillus fumigatus’, ‘Cryptococcus neoformans’, ‘Candida auris’, and ‘Candida albicans’, along with the names of novel antifungal substances, including ‘fosmanogepix’, ‘ibrexafungerp’, ‘opelconazole’, ‘oteseconazole’, ‘MAT2203’, ‘olorofim’, and ‘rezafungin’ was conducted. ContentFor each critical pathogen, current issues and global clinical data from recent trials are covered. The remarkable development of three new antifungal therapeutics recently receiving Food and Drug Administration approval (ibrexafungerp—June 2021, oteseconazole —April 2022, and rezafungin—March 2023) is outlined, with two more exciting new antifungal substances, namely, olorofim and fosmanogepix expecting approval within the next years. Ibrexafungerp, fosmanogepix, and rezafungin have additionally been granted orphan drug status by the European Medicines Agency in Europe (ibrexafungerp—November 2021, fosmanogepix—July 2022, and rezafungin—January 2024). ImplicationsAlthough the limited number of targets and the emergence of resistance have posed challenges to antifungal treatment, new drugs such as ibrexafungerp, rezafungin, fosmanogepix, or olorofim have shown promising clinical efficacy. These drugs not only provide alternative options for invasive fungal infections but also alleviate treatment in outpatient settings. More clinical data, implementation of stewardship programmes, and surveillance, including utilization of drugs in agriculture, are necessary to prevent resistance development and to ensure the safety and efficacy of these new agents.

Introduction. A lot of plant produced essential oils, which are applied in prophylaxis and therapy of medicine. Melissa was known and used in I century BC. It produced the oil, which possess following properties: antiarteriosclerotic, anticancer, sedative, antidepression, antimigraine, antiasthmatic, antirheumatic and antioxidant. Its contain: geraniol, β-caryophyllene, geranial, thymol, neral, geranyl acetate, linalol, cytronellol, citronellal and α-humulen. It exhibited antibacterial and antifungal activity. Aim. The aim of this study was to indicate of susceptibility of yeastlike fungi to melissae essential oil. Material and methods. The strains of fungi were isolated from oral cavity from patients with candidosis. A total 23 strains of yeastlike fungi from genus of Candida albicans (22 strains), C. glabrata (5), C. guilliermondii (2), C. humicola (2), C. kefyr (3), C. krusei (5), C. lusitaniae (2), C. parapsilosis (5), C. tropicalis (6), C. utilis (1) and 9 reference strains were tested. Investigated was carried out using plate dilution technique in Sabouraud’s agar. The melissae oil (Semifarm) was dissolved in DMSO and then in aseptic distilled water. Inoculum contain 105 CFU per spot was transferred with Steers replicator upon the agar with and without essential oil (strains growth control). The concentrations of melissae oil were: 2.0, 1.0, 0.5, 0.25 and 0.12 mg/ml. Incubation was performed in aerobic conditions in temp. 37°C. Incubation of agar plates were performed in aerobic condition at temp. 37°C, at 24-48 hours. Minimum inhibitory concentration (MIC) was interpreted as the lowest concentrations of melissa oil which inhibited the growth of yeastlike fungi. Results. The dates indicated that the strains of fungi was susceptible to oil in concentrations 0.25-2.0 mg/ml. The 19 (86%) of strains from genus Candida albicans was inhibited in concentrations 0.25-0.5 mg/ml. On the same values of MIC’s were susceptible the strains of Candida albicans, Candida glabrata and Candida humicola (MIC 0.5 mg/ml). The fungi from genus of Candida kefyr, Candida krusei, Candida lusitaniae and Candida tropicalis were less sensitive. The growth of this yeastlike fungi was inhibited by concentrations of melissae oil in range 0.5-2.0 mg/ml. The oil was the lowest active towards genus Candida lusitaniae and Candida utilis. The MIC for these strains was from 1.0 to 2.0 mg/ml. From all tested genus Candida strains 11 (21%) of them was susceptible to melissa oil in range 2.0 mg/ml. Conclusions. Melissa oil was the most active towards strains of Candida albicans, Candida glabrata and Candida humicola. The lowest sensitive to oil were the strains from genus Candida lusitaniae and Candida utilis. The melissa oil characterized a high activity towards all tested strains of yeastlike fungi from genus of Candida.