Black Pigment Research Articles

HPB SO11 - Dropped Gallstones After Laparoscopic Cholecystectomy: An Umbrella Review

Abstract Background Gallstones (cholelithiasis) are solid formations in the gallbladder or biliary tract due to high cholesterol or bilirubin levels, affecting 10-20% of adults. Over 20% of those affected show symptoms like biliary colic. Gallstones can be cholesterol, black pigment, or brown pigment, with cholesterol stones being the most common. The persistence of gallstones following laparoscopic cholecystectomy (LC) poses a significant clinical challenge, potentially leading to morbidity and diagnostic complexities, often with delayed recognition. These complications can present as various intraabdominal conditions such as abscesses (intraabdominal or abdominal wall), fistula formation, peritonitis, bowel perforation, or ileus. Method We performed an extensive search of the academic literature spanning several databases, namely PubMed, Embase, Scopus, Web of Science, and Google Scholar. Inclusion criteria for this research encompassed systematic reviews, with or without meta-analysis, focusing on the examination of spilled gallstones in terms of signs, symptoms, diagnosis, imaging, and management. The assessment of potential bias in the final study selection was undertaken utilizing the R-AMSTAR and Risk of Bias in Systematic Reviews (ROBIS) assessment tools. Results The most prevalent sites for lost gallstones were identified as the right subhepatic, perihepatic, retroperitoneal, right flank, and pelvic regions. Multiple stones were found to be more common than single stones. Clinical presentations included the presence of abdominal masses simulating malignancy, intestinal obstruction, and pelvic pain or fistula formation. Surgical intervention emerged as the primary treatment approach. Pain localized to the right upper quadrant was reported by 24% of participants. Computed tomography (CT) was the most frequently employed diagnostic modality for stone identification (70.2%), followed by ultrasonography (US) (63.2%) and X-ray (42.9%). Conclusion Our research underscores a significant area that has received limited attention in existing literature. The occurrence of spilled gallstones presents challenges in diagnosis and carries the potential for severe post-laparoscopic cholecystectomy complications. A notable gap exists in the education of both surgeons and patients regarding this complication, emphasizing the need for heightened awareness among surgeons. Given the considerable variability observed between laparoscopic cholecystectomy procedures and the onset of associated symptoms, comprehensive studies with larger cohorts are imperative for elucidating pertinent risk factors and devising effective interventions.

Development of protein hydrolysate as a cost-effective and robust biodispersant: Investigating its performance in dispersing of carbon black pigment in water-based paints

Carbon black pigments hold significant importance as the primary representatives of black pigments in the industry today. The dispersibility of carbon black pigment (CB) in water is limited by the nonpolar and weakly hydrophilic characteristics of the pigment's surface. Therefore, there is a critical need to devise an economical and eco-friendly approach for creating a well-dispersed and stable suspension of carbon black in an aqueous medium. The primary focus of this study was to investigate the dispersion capabilities of protein hydrolysate (HP) derived from sheep wool on CB particles in a water-based pigment concentrate. The hydrolysis degree of protein source was determined by high-performance liquid chromatography and gel permeation chromatography. The dispersion performance was investigated by zeta potential, transmission electron microscopy, Fourier transform infrared spectroscopy, grindometer, spectrophotometer-colorimeter, viscometer, and cryptometer measurements. The HP solution containing amino acids, peptides, and polypeptides with low molecular weight can cover the surface of the CB particles, creating enough electrical repulsion and steric resistance. As a result, this phenomenon can inhibit the collision and interaction among the pigment particles caused by Brownian motion, making it less prone to aggregation. The protein hydrolysate demonstrated a higher capability in producing the stable CB dispersions compared to a commercial reference dispersant, highlighting the effectiveness of amino acids, peptides, and polypeptides as powerful CB dispersing agents.

Bilateral hip ochronosis, an unsuspected diagnosis in polyarticular pain: A case report

Alkaptonuria is a rare metabolic disorder characterized by the accumulation of homogentisic acid, leading to the deposition of blackish pigment in cartilage and soft tissue, known as ochronosis. This can mimic multiple joint pathologies and is a diagnosis of exclusion. We describe the case of a 52-year-old woman who had a total hip replacement after experiencing left hip pain for which oral medications were unable to provide relief. Unexpectedly, during the procedure, a blackish tissue was noticed. This led to a histological examination and the confirmation of the ochronosis diagnosis. The patient’s medical history revealed a number of malignancies, but no previous metabolic illness diagnoses. Subsequent follow-up revealed rapid-onset pain in other joints, leading to a similar diagnosis of polyarticular ochronosis in the right hip, knees, spine, and shoulders. This highlights how difficult it is to treat this condition. This case underscores the importance of considering ochronosis as a differential diagnosis in patients with chronic polyarticular pain. Current treatment consists of initial non-surgical measures, including physical therapy and analgesics. If there is no improvement, treatment would be joint arthroplasty. Awareness among orthopedic surgeons and histopathological examination of tissues is crucial for the accurate diagnosis and management of ochronosis.

Designing LiDAR‐Detectable Dark‐Tone Materials with High Near‐Infrared Reflectivity for Autonomous Driving: A Comprehensive Review

AbstractAutonomous driving relies on the precise recognition of objects using light detection and ranging (LiDAR) technology, that operates at a specific wavelength of 905 nm. Black objects, such as carbon black used in vehicle coating, tend to absorb this specific wavelength significantly, which limits the performance of LiDAR sensors. To address this issue, researchers have explored creating dark‐toned materials that can be detected by LiDAR with high NIR reflectivity while maintaining a true blackness (L* < 20 based on the CIE color coordinates). These materials fall into two categories: organic and inorganic pigments. Organic pigments can be synthetically adjusted to achieve true blackness by manipulating their functional groups, but achieving high NIR reflectivity remains challenging, often requiring a bilayer structure with NIR‐reflective white base and an upper layer of organic black pigments. Additionally, the need for hydrophobic additives and resistance to degradation from sunlight further restricts their use. In the case of inorganic pigments, the desired LiDAR‐detectable properties can be obtained through careful control of their composition, structure, and morphology, allowing for single‐layer coatings with appropriate design. This review highlights recent advancements in developing organic and inorganic LiDAR‐detectable black pigments and outlines future material design strategies for autonomous vehicle systems.

Size-Controlled LiDAR-Detectable Black Pigments: Comparative Study from the Nano- to the Micron-Scale

Size-Controlled LiDAR-Detectable Black Pigments: Comparative Study from the Nano- to the Micron-Scale

Novel Co and Cr free, high-temperature black ceramic pigment based on (Ni, Mn) co-doping (CuFe)Fe4O8

Novel Co and Cr free, high-temperature (Ni, Mn) co-doping (CuFe)Fe4O8 black ceramic pigment was synthesized. The results indicate that the brightness (L*) values of the synthesized pigments decrease first, then reach an optimal value, and then increase with the doping amounts increasing of both Ni2O3 and MnO2. The optimized Ni2O3 and MnO2 doping amounts are 0.20 (molar ratio to (CuFe)Fe4O8) and 0.75 (molar ratio to (CuFe)Fe4O8), respectively. L*, a* and b* values of the optimized pigment (0.20Ni, 0.75Mn) co-doping (CuFe)Fe4O8 are 21.36, 1.10 and −0.24, respectively. The crystal phase of the optimized pigment is (CuFe)Fe4O8 (JCPDS73–2314). The crystal size of the pigment is 0.8–1.5μm with excellent dispersivity. The glazing temperatures have little effect on the coloration of the pigment when used at 1000℃, 1150℃ and 1300℃. The results show that the pigments have excellent high-temperature resistance and are expected to be widely used in high-temperature glazing coloration.

Rare Case of Subcutaneous Phaeohyphomycosis Caused by Exophiala jeanselmei

Abstract Introduction/Objective Phaeohyphomycosis is a neglected tropical infection caused by dematiaceous fungi containing melanin in their cell wall. Currently, the prevalence of phaeohyphomycosis is very low in the United States compared to other mycotic agents. Trauma often precedes phaeohyphomycosis, and there are a limited number of cases associated with healthcare settings. This case report describes a nosocomial phaeohyphomycosis caused by Exophiala jeanselmei. Methods/Case Report A 60-year-old male with multiple myeloma, on immunosuppressive therapy, presented with a large fluctuant mass on the dorsum of his right hand. The mass had developed 6 months ago as a hematoma following a blown vein during a blood draw. Despite treatment with antibiotics, the mass continued to grow. The patient underwent surgical excision of the lesion, and the purulent aspirate was sent to the microbiology lab. Aerobic, anaerobic, mycobacterial, and fungal cultures, along with Gram and AFB stains, were performed. Direct microscopy of the aspirate revealed numerous leukocytes and few yeast cells. No sclerotic bodies were observed. Fungal growth with black pigmentation was observed during the second week of incubation. Colonies initially appeared smooth black and mucoid, later transforming into raised dome-shaped structures with a suede-like texture. Microscopic analysis revealed budding yeast cells and subglobose to broadly ellipsoidal germinating cells, which developed into short torulose hyphae before gradually transforming into unswollen hyphae. The isolate was further identified through D2 rDNA sequencing, revealing a 100% match for Exophiala jeanselmei. The patient was prescribed a one-month course of itraconazole treatment. The patient is progressing well during follow-up. Results (if a Case Study enter NA) NA Conclusion This case emphasizes the need for heightened clinical awareness in diagnosing phaeohyphomycosis, particularly in healthcare environments. Unique traumatic events like venepuncture should raise suspicion of phaeohyphomycosis. Culture and molecular diagnostics play a crucial role in confirming fungal causes and guiding treatment, leading to better patient outcomes.

Enhanced NIR reflectance black pigments based on CuCr2-xTixO4: Synthesis and properties

Ti-doped CuCr2O4 is an excellent black cool pigment for preventing surface overheating. Ti was introduced into the precursor in the form of tetrabutyl titanate(C16H36O4Ti) and calcined to obtain a CuCr2-xTixO4 black pigment. XRD, XPS, and EDS results showed that a portion of Ti entered the lattice of CuCr2O4, while the remaining Ti existed in the form of TiO2. The absence of TiO2 reduced the absorption of visible light. As the x value increased, the absorption of visible light by CuCr2-xTixO4 decreased and L* increased. CuCr1.1Ti0.9O4 has a maximum reflectance of 23.0% for NIR solar reflectance, and the mechanism could be determined by the following three reasons: 1) Small particles help to reflect NIR; 2) TiO2 improves the NIR reflectivity of the black pigment; and 3) According to the Drude free-electron theory, the substitution of Ti4+ for Cr3+ increases the concentration of free carriers in CuCr2O4, which increases the NIR reflectance. Application studies indicated that the CuCr1.1Ti0.9O4 coating on an alumina plate was approximately 3 °C lower than the CuCr2O4 coating after 40 minutes of irritation by an IR lamp. Therefore, CuCr1.1Ti0.9O4 pigments exhibited potential applications in insulating materials.

Minimizing the cobalt content in black ceramic pigments by Design of Experiments

This paper presents a comprehensive optimization strategy for the synthesis of new black ceramic pigments with low cobalt content while maintaining a single-phase spinel structure. The aim is to achieve comparable hues to those of an industrial benchmark containing five transition metals while minimizing the environmental impact. Exploring all possible compositions deriving from a five–component system (Cr, Mn, Fe, Co and Ni), through traditional methods would be extremely time consuming to guarantee an efficient sampling, requiring high experimental efforts. Hence, to identify the best black compositions, we employed a chemometric approach, the Design of Experiments, aiming to investigate the compositional domain derived by varying the metals stoichiometry within fixed boundaries to identify optimal pigment compositions. The resulting pigments (comprising Cr, Fe and Co), despite the lower cobalt content, exhibited optimal colorimetric properties comparable to the standard benchmark, with experimental ΔE values comparable to the ones predicted by the model. In particular, the pure spinels Cr1.05Fe1.05Co0.9O4 and Cr1.2Fe1.05Co0.75O4 displayed low lightness and chroma (L∗ = 2.4; C∗ = 5 and L∗ = 1.12; C∗ = 1.1, respectively), providing deep and dark black tonality. These compositions exhibit promising colorimetric performance and chemical stability, offering potential benefits for industrial applications.

The Production of Melanin Pigments From Some Pathogenic Fungi in Response to L-Tyrosine Under Laboratory Conditions

Background: This study aims to evaluate response of plant pathogenic fungi to the amino acid L-tyrosine through the production of melanin. Methods: Potato dextrose broth (PDB) and PDB with 1% L-tyrosine were used for current evaluation. Melanin was produced, extracted and characterized from pathogenic fungi that infected rice in Iraq. Results: Results indicated that L-tyrosine was used as a source of the precursor by fungi belonging to Bipolaris. spicifera R15, Alternaria. alternata R18, Exserohilum. rostratum R19, Alternaria. alternate R20, and Alternaria. tenuissima R23, also produced higher levels of condensed black pigment. While, fungi like Nigrospora oryzae R9, Curvularia lunata R7, C lunata R21 and A tenuissima R24 were used more than one pathway for melanin production. UV transmittance increased significantly from 600 nm to 300 nm whereas absorbance decreased at 260 and 280 nm for all of the studied fungi. Analysis of FT-IR spectra and related assignment group of resolved that melanin extracted from B. spicifera R15 (3408.22), A. alternate R20 (3392.79), and A. tenuissima R24 (3387). Wavenumbers 2924 cm−1 and 2854 cm−1 were found in E. rostratum R19, A. alternative R20, and A. tenuissima R24 melanin extracts, respectively. Meanwhile, B. spicifera R15 revealed a single peak at 2929 cm−1. 3007.02 cm−1, 3072.6 cm−1, 3074.53 cm−1, 2920.3 cm−1, 2704.2 cm−1, and 1861.31 cm−1 are also assigned wavenumbers. Conclusion: Melanin-like pigments are produced via L-tyrosine-dependent and independent pathways. All colors extracted from fungal hyphae were morphologically and chemically identical to melanin. A UV scan and FT-IR analysis revealed differences in the physical appearance of building units and the structure of the melanin pigment produced by plant pathogenic fungi.

Titania-Based Coral-Structured Solar Absorber Coating with Improved Scalability and Durability at High Temperature.

Solar energy harvesting and storage are essential in the future mix of renewable energy technologies. Hierarchical coral-structured coatings have been shown to yield high solar absorptance in concentrating solar thermal (CST) systems. However, interfacial delamination and scalability challenges owing to material complexity pose significant hurdles for the widespread industrial adoption of these hierarchical CST coatings. Here, a coral-structured coating is proposed whose black pigments are strongly bonded by titania, which is a material that mitigates interfacial delamination. Importantly, this coating follows a facile deposition procedure suitable for large-scale solar receivers. The drone-deposited coating inhibits cation diffusion and maintains a stable solar absorptance of even after long-term (3000 h) high-temperature ( ) aging. The scalability of developed coating represents a substantial advancement in the implementation of light-trapping enhancement and maintenance approaches across a wide range of CSTapplications.

A New Method Proposed for the Estimation of Exposure to Atmospheric Pollution through the Analysis of Black Pigments on the Lung Surface

Megacities can be considered excellent laboratories for studying the effects of the urban environment on human health. Typically, exposure to pollution is estimated according to daily or annual averages of pollutant concentrations, collected at monitoring stations, using satellite data for remote sensing of pollutant levels, considering proximity to major roads, or through personal exposure monitoring with portable sensors. However, these approaches fall short in identifying individual exposure values over a lifetime. It is well established that individuals living in large urban areas inhale atmospheric particles containing carbonaceous components, resulting in the deposition of black pigments in lung tissue, known as black carbon or anthracosis. This study aims to detail the procedures for assessing the deposition of such pigments, which serve as an estimate of an individual’s exposure to atmospheric pollution particles. Data collection involves administering detailed questionnaires and capturing lung images in the autopsy room. The analysis is based on macroscopic quantification of black pigments, supplemented by an evaluation of personal habits and the clinical histories of the individuals. This method of estimating lifetime exposure to inhaled particles provides a valuable tool for understanding the correlation between urban living and its potential health effects.

A rare differential diagnosis of aortic stenosis with a black aortic valve: A case report

BackgroundCardiac ochronosis, presenting as a rare manifestation of alkaptonuria, an autosomal recessive disorder, is characterised by black pigmentation of calcified cardiac valves and atherosclerotic plaques. We report an intraoperative dilemma on the discovery on the black aortic valve in a case of an old lady with degenerative calcific aortic stenosis.Case presentationA 60-year-old lady was electively admitted for valve replacement with a bioprosthetic valve for severe aortic stenosis. She was symptomatic with complaints of headache and giddiness and had a pressure gradient of 113/17mmhg across the aortic valve. Intraoperatively, she was found to have cardiac ochronosis on the discovery of pigmented aortic intima extending to the valve leaflets and underwent valve replacement with a mechanical prosthetic valve. She was post-operatively evaluated for the same and diagnosed with alkaptonuria. Though the surgery went uneventful and the patient was discharged without any complication, she was advised to be on regular follow-up to assess valve gradients, paravalvular leaks and to monitor the disease progression.ConclusionThe presented case sheds light on the rare cardiac manifestation of alkaptonuria. In the absence of definitive pre-operative diagnosis, intraoperative findings played a pivotal role in guiding the surgical approach and choice of prosthetic valve. The decision to use a mechanical valve was influenced by the potential risks associated with bioprosthetic valves in the setting of ochronosis. Ongoing follow-up and monitoring are essential to assess the durability of the chosen prosthetic valve and to manage any long-term consequences of the underlying metabolic condition.

Transcriptome profiles of the skin associated with the color of the black and white coat of Angora goats

The coat color of mammals, determined by the distribution of melanin, particularly eumelanin and pheomelanin, reflects intricate genetic and molecular processes. However, our understanding of the relationship between coat color, gene expression, and polymorphisms in goats remains nascent. This study investigates transcriptomic differences between black and white Angora goats across three distinct hair growth phases. Skin tissue samples from both colored and white Angora goats were analyzed using mRNA expression profiling. Three skin samples were taken from each goat as biological duplicates at every stage of hair follicle growth (September, January, and March). In total, 36 samples were analyzed in this study, including samples from two Angora goat varieties, three developmental stages (three biological replicates), and two technical replicates for RNA sequencing. Significant differences in gene expression were observed between black and white goats at each growth phase, particularly in genes associated with the melanogenesis pathway. Specifically, several pigmentation genes were identified solely in black goats, indicating phase-specific and breed-specific regulation. Noteworthy genes, such as SLC2A1, STAR, and SLC7A5, exhibited differential expression patterns across growth phases in black goats, further highlighting the complexity of melanogenesis regulation. This is the first study to use mRNA expression profiling of skin tissues to analyze coat color differences between black and white coated Angora goats at the anagen, catagen, and telogen stages. The identification of phase-specific and black goat-specific pigmentation genes provides valuable insights into the complex mechanisms governing coat color formation.

The Roman villa at the Castle of Baia (Naples, Italy): investigations on the polychromy of frescoed surfaces by using non-destructive spectroscopic techniques

During the Roman age, the southern promontory of the gulf of Baia was the perfect location for the construction of villae maritimae for the Roman élite that decided to spend their summer residences by the sea.One of these residences is now located in the military fortress of the Castello Aragonese di Baia, built in 1495 CE during the Aragonese period (15th century). Here, during restoration works, the ruins of the residential sector of the villa, which historical sources ascribe to Caesar, were unearthed. The most representative evidence of this is the outstanding in situ remain of mosaics, decorated plasters and finely frescoed surfaces decorated according to the repertoire of the II style. This research aims to investigate the polychromy of a wall decoration representing a perspective depiction of architectural scenes en trompe l'oeil analysed by means of a multi-analytical, non-destructive approach performed in situ. The combined use of spectroscopic techniques (portable X-ray fluorescence, Raman and Fourier Transform Infrared Spectroscopy) points out the use of a characteristic Roman palette, quantitatively assessed by colorimetric measurements. It consists of red and yellow ochre, calcite, hematite, organic black pigments, precious materials such as cinnabar and Egyptian blue, green copper compounds. Fourier Transform Infrared Spectroscopy also revealed the presence of synthetic resins, likely used for the conservation of mural paintings. These are, however, damaged by atmospheric humidity, as detected by Infrared Thermography. Gypsum has been identified as the main weathering product.

Future Parabolic Trough Collector Absorber Coating Development and Service Lifetime Estimation

This work presents a study on the optical and mechanical degradation of parabolic trough collector absorber coatings produced through the spray coating application technique of in-house developed paint. The main aim of this investigation is to prepare, cure, load, and analyze the absorber coating on the substrate under conditions that mimic the on-field thermal properties. This research incorporates predicted isothermal and cyclic loads for parabolic trough systems as stresses. Biweekly inspections of loaded, identical samples monitored the degradation process. We further used the cascade of data from optical, oxide-thickening, crack length, and pull-off force measurements in mathematical modelling to predict the service life of the parabolic trough collector. The results collected and used in modelling suggested that cyclic load in combination with iso-thermal load is responsible for coating fatigue, influencing the solar absorber optical values and resulting in lower energy transformation efficiency. Finally, easy-to-apply coatings made out of spinel-structured black pigment and durable binder could serve as a low-cost absorber coating replacement for a new generation of parabolic trough collectors, making it possible to harvest solar energy to provide medium-temperature heat to decarbonize future food, tobacco, and paint production industrial processes.

“Mechanic’s Hand” with Polyarthralgia and Transient Autoimmune Features after COVID Vaccination

Abstract Autoimmune diseases are now well reported with COVID vaccination. Rheumatological, neurological, cardiac, and hematological adverse events are observed globally. Dermatological adverse events are reported in a few cases but dermatological with rheumatological manifestation with reversible autoimmune phenomenon after COVID vaccination is not reported commonly in literature. “Mechanic’s hands” is blackish discoloration of palmar aspects of both hands and knuckles commonly reported in rheumatological autoimmune condition such as dermatomyositis. In this case report, a 28-year-old male presented with polyarthralgia with myalgia and fatigability after 1 month of COVID vaccination. His joint pain symptoms worsened over 4 weeks and developed blackish pigmentation of both hands predominantly involving palms to present as mechanic’s hands. Vasculitis workup was inconclusive and rheumatologic workup documented raised antinuclear antibody titers and rheumatoid factor. We have started him on steroid and hydroxychloroquine and observed satisfactory clinical response with near complete resolution of “mechanic’s hands” in 24 weeks. Mechanic’s hands with rheumatological syndrome which is a rare vaccine-related adverse event, reversible, and easily treatable with routinely available medicines, and importantly it is having excellent prognosis. Mechanic’s hand is first time reported in medical literature after COVID vaccination. Minimal systemic adverse events are known to occur with all viral vector vaccines, but its occurrence is rare and it should not impact on routine vaccinations, as vaccination is a key step in this pandemic to protect humankind.

Diagnosis and Treatment of an Unusual Maxillary Gingiva Malignant Melanoma Arising Around Dental Implant.

Oral mucosal malignant melanoma (OMMM) arises from malignant melanocytes, and the most affected age, sex, and site are 20 to 83 years, male, and the mucosa of hard palate and maxillary gingiva, respectively. Despite several cases of OMMM have been published in the literature, cases of malignant melanoma arising around the dental implant are rarely reported. A 59-year-old male was admitted to our Department with the complain of gingival black pigmentations following dental implant treatment for 3 years. Intraoral examination revealed a painless black lobulated mass around maxillary gingiva and alveolar fossa of dental implant (first molar). CBCT revealed bone destruction around the implant. Positron emission tomography/computed tomography confirmed the presence of tumoral lesion, which was diagnosed as right maxillary gingiva malignant melanoma (T4aN0M0). Partial maxillectomy+buccal fat pad transfer+free tissue patch repair were carried out. Pathologic analyses confirmed the diagnosis of malignant melanoma. The postoperative course was uneventfully, the patient is undergoing follow-up without any evidence of recurrence. Our report showed that an ill-fitting dental implant may cause OMMM. Excisional biopsy with sufficient surgical margins allows complete removal and final diagnosis of OMMM. Early diagnosis and treatment are recommended.

Deciphering the salt induced morphogenesis and functional potentials of Hortaea werneckii; a black pigmented halotolerant yeast isolated from solar saltern

An intense black pigmented halotolerant yeast GUBPC1, was obtained from the solar salterns of Nerul, Goa-India. The isolate could tolerate 0 to 20 % NaCl. FE-SEM analysis revealed its polymorphic nature, exhibiting oval cells at higher salt concentrations and filamentous spindle like shapes at lower concentrations. Initially, the cells appear oval, yeast like in shape but gradually after 15 days of incubation, it becomes elongated and undergoes budding, exhibiting various budding patterns, from single polar bud to bipolar buds with annellidic ring, to lateral buds and eventually forming filamentous hyphae. The intracellular black pigment was identified as melanin based on ultraviolet–visible spectroscopy analysis. The molecular identification of the culture showed closest similarity with Hortaea werneckii. Plant polymer-degrading enzymatic activities such as cellulase, laccase, chitinase, xylanase, pectinase, amylase and protease were exhibited by the isolate GUBPC1. To further understand and explore its biotechnological potential, we performed whole-genome sequencing and analysis. The obtained genome size was 26.93 Mb with 686 contigs and a GC content of 53.24 %. We identified 9383 protein-coding genes, and their functional annotation revealed the presence of 435 CAZyme genes and 16 functional genes involved in secondary metabolite synthesis, thus providing a basis for its potential value in various biotechnological applications.

Biocompatible melanin from the marine black yeast Hortaea werneckii R23 with antioxidant and photoprotection property.

Pigments from diverse sources have a great deal of interest due to its multifaceted applications. Hence, this study reports the physicochemical and functional characterization of the black pigment melanin from the marine black yeast Hortaea werneckii R23. In the present study, Hortaea werneckii R23, produced a black pigment in the yeast biomass. The pigment was extracted from the harvested yeast biomass and followed by pigment purification, characterization and identification was done. Physicochemical characterization of the pigment showed acid precipitation, alkali solubilization, insolubility in most organic solvents and water. The black pigment was confirmed as melanin based on ultraviolet-visible spectroscopy, Fourier-transform infrared, and Nuclear magnetic resonance spectroscopy analyses. Furthermore, the analyses of the elemental composition indicated that the pigment possessed a moderately high percentage of nitrogen and also detectable proportion of sulfur. All these Physicochemical properties indicated that H. werneckii melanin (HwM) mostly consisted of eumelanin. HwM exhibited strong antioxidant potential as reactive oxygen species (ROS) scavenger by in vitro DPPH (1,1-diphenyl-2-picryl hydrazyl) and ABTS (2,2-azinobis-3-ethyl-benzothiozoline-6-sulphonic acid) radical scavenging assay, and lipid peroxidation assay. The photoprotectant role of HwM on UV-irradiated human epithelial cells (HEp-2) revealed its potential effect in photoprotection. In addition, cytotoxicity study by XTT and SRB assay confirmed its biocompatibility with HEp-2 cells. From these findings, it is evident that the HwM from the marine black yeast possesses strong antioxidant and photoprotectant activity, moreover, it is biocompatible to human epithelial cells. So HwM could be used as a protective agent against oxidative stress associated disorders in an environment-friendly perspective.