The surfaces of historical stone monuments are visibly covered with a layer of colonizing microorganisms and their degradation products. In this study, a metadata analysis was conducted using the ...microbial sequencing data available from NCBI database to determine the diversity, biodeterioration potential and functionality of the stone microbiome on important world cultural heritage sites under four different climatic conditions. The retrieved stone microbial community composition in these metagenomes shows a clear association between climate types of the historical monuments and the diversity and taxonomic composition of the stone microbiomes. Shannon diversity values showed that microbial communities on stone monuments exposed to dry climate were more diverse than those under humid ones. In particular, functions associated with photosynthesis and UV resistance were identified from geographical locations under different climate types. The distribution of key microbial determinants responsible for stone deterioration was linked to survival under extreme environmental conditions and biochemical capabilities and reactions. Among them, biochemical reactions of the microbial nitrogen and sulfur cycles were most predominant. These stone-dwelling microbiomes on historical stone monuments were highly diverse and self-sustaining driven by energy metabolism and biomass accumulation. And metabolic products of the internal geomicrobiological nitrogen cycling on these ancient monuments play a unique role in the biodeterioration of stone monuments. These results highlight the significance of identifying the essential microbial biochemical reactions to advance the understanding of stone biodeterioration for protection management.
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•A metadata analysis of microbiota was conducted for 4 global climate types with 12 samples.•A significant difference in the alpha diversity was detected among the 4 different climates.•Important biochemical functions are related to survival and major element cycling.•N transformation reactions of ammonia/ammonium oxidation and reduction were particularly active.
Eukaryotic microorganisms are ubiquitous in the marine environment, and have a wide variety of ecosystem functions. Shenzhen is one of the most developed cities in South China, but the eukaryotic ...communities in the water along its coastlines remain poorly understood. The study applied 18S rRNA gene ITS (internal transcribed spacer) sequencing to identify the eukaryotic community from twenty sites of Shenzhen coast water. The alpha-diversity of the samples between these sites were significantly different, and the seawater of eastern coast had higher alpha-diversity compared to that of the western coast. The abundance of
Chlorophyta
was notably higher in the seawater of western coast, but
Picozoa
was relatively depleted. Specifically,
Cryptocaryon
,
Pseudovorticella
, and
Cyclotella
were significantly higher in the water of western coast, while
Guinardia
,
Minutocellus
, and
Amoebophrya
were increased in eastern samples. The spatially variations of eukaryotic microorganism community in the seawater of Shenzhen coast were associated with the water quality. The results have important significance for the understanding of coastal eukaryotic community, their interaction network, and build a foundation for future management and protection of coastal water quality.
The ancient Angkorian sandstone monuments in Cambodia are well known for biodeterioration of the sandstone under tropic climate. This study examined ammonia oxidizing bacteria (AOB and Comammox) and ...archaea (AOA) in stone-dwelling microbiome from three important Angkor monuments, namely Angor Wat, Bayon of Angkor Thom, and Preah Vihear, by DNA-based metagenomics analysis, RNA-based functional gene reverse-transcriptional (RT)-qPCR quantification, and N-15 isotope analysis. Our metagenomics datasets on these three monuments reveal a rich microbiome and abundant microbial nitrogen transforming reactions of ammonia oxidation and nitrite oxidation, Comammox and dissimilatory nitrate reduction to ammonium (DNRA), and these results support an internal recycling mechanism between ammonia/ammonium and nitrate by AOA, AOB, Comammox and DNRA on the stone monuments to support the microbial community. Though a wide range of AOB and AOA lineages together with Comammox were retrieved from these metagenomes as the potential ammonia-oxidizers, only AOA and Comammox were most abundant, likely to contribute to the biochemical processes of ammonia oxidation. The RNA-based qPCR quantification of the functional gene amoA in this study showed that AOA were the more active ammonia oxidizers over AOB in the microbiome of these Angkor sandstone monuments. In addition, a rich population of nitrite/nitrate producing AOA and Comammox drove the sequestration of CO2 onto the stone and this process was in turn supported by DNRA to provide the substrate ammonia/ammonium for a further cyclic reaction to take place continuously between ammonia/ammonium and nitrate. This model is further supported by the high enrichment of stable isotope 15N signature of NO3− in sandstone surface biofilms. The findings of this study are insightful for elucidation of nitrate accumulation by an internal N cycling mechanism proposed, and are important for understanding the sustainable microbial community and protection management of stone cultural heritage.
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•Nitrate accumulation on Angkor sandstone monument was investigated with sequencing and also isotope analyses.•Ammonia-oxidation was mainly by AOA and Comammox bacteria.•DNRA as an important contributor to lowering the nitrate contraction and also providing substrate.•An internal cycling mechanism was discovered between ammonium and nitrate.
Seashore habitats are located between terrestrial and marine ecosystems, which are a hotspot for anthropogenic impacts. Shenzhen is one of the most developed cities in south China, but the microbial ...functions of its coastal ecosystems remain poorly understood. The study applied 16S rRNA gene sequencing methods to identify the bacterial community from twenty sites of Shenzhen inshore waters. The microbial structure of the samples between eastern Shenzhen and western Shenzhen seashores is notably different, suggesting the spatial variability.
Proteobacteria
,
Cyanobacteria
,
Actinobacteria
, and
Bacteroidetes
were dominant phyla in the community, and the relative abundance of
Bacteroidetes
was significantly higher in eastern seashores. Specifically, samples from western Shenzhen contained much more
Prochlorococcus
, while
Synechococcus
was more abundant in eastern samples. Moreover, the metabolism of terpenoids and polyketides, and transport and catabolism were significantly more abundant in eastern samples, while antibiotic-resistant pathways were enriched in western samples. The results have important significance to understand bacterial ecosystem of coastal water and promote water quality management and protection activity in Shenzhen. This study can also help developing an optimal strategy for the green economy development and the policy planning of Guangdong-Hong Kong-Macao Greater Bay Area.
World cultural heritage suffers from deterioration caused by both natural and anthropogenic processes, among which microorganisms are significantly involved. Among the key issues of this topic, ...sampling techniques and analytical methods for revealing the microbiome are fundamental to obtaining useful results for understanding the key players and processes involved, and also for effective protection and management of the cultural heritage for humanity. A non-invasive and non-destructive sampling method is required for sampling of cultural properties prior to further analysis of the microbiome. One example is illustrated in this article. For many years, culture-dependent methods had been used before the invention of polymerase-chain reaction (PCR) methods and, more recently, specifically high-throughput next generation sequencing (NGS). NGS reveals the whole microbial community composition and the active microorganisms from genomic DNA and RNA, respectively. The recovered environmental DNA and RNA from samples provide the information on microbial community and composition, and the active members and biochemical processes of the microbial attributes. It should be emphasized that the metabolically-active members of functional microflora in the biofilm or microbiome on cultural heritage must be determined and identified from the RNA-based analysis to gain a substantially important insight of the active biodeterioration processes and also the effectiveness of the conservation strategies. The importance of the culture-independent technique, based on NGS, is that it can be used in combination with the conventional culturing methods to guide the isolation and enrichment of new microorganisms to gain further biochemical insights to advance the role of the specific microbial groups for biodeterioration of cultural heritage. At the same time, effective restoration and maintenance strategies can be formulated for the protection of world cultural heritage.
Anammox bacteria have been detected in various ecosystems, but their occurrence and community composition along the shipping channels have not been reported. In this study, anammox bacteria were ...recovered by PCR-amplified biomarker
hzs
B gene from the genomic DNA of the sediment samples. Phylogenetic tree revealed that
Candidatus
Scalindua and
Ca
. Brocadia dominated the anammox community of the Hong Kong channels;
Ca
. Scalindua spp. was present abundantly at the sites farther from the shore, whereas
Ca
. Jettenia and
Ca
. Kuenenia were detected as the minor members in the estuarine sediments near the shipping terminals. The highest values of Shannon–Wiener index and Chao1 were identified in the sediments along the Urmston road (UR), suggesting the highest α-diversity and species richness of anammox bacteria. PCoA analysis indicated that anammox bacterial communities along UR and Tai Hong (TH) channel were site-specific because these samples were grouped and clearly separated from the other samples. The maximum diversity of anammox bacteria was detected in UR samples, ranging from 6.28 × 10
5
to 1.28 × 10
6
gene copies per gram of dry sediment. A similar pattern of their transcriptional activities was also observed among these channels. Pearson’s moment correlation and redundancy analysis indicated that NH
4
+
-N was a strong factor shaping the community structure, which showed significant positive correlation with the anammox bacterial abundance and anammox transcriptional activities (
p
< 0.01,
r
> 0.8). Also, NH
4
+
-N, (NO
3
−
+ NO
2
−
)-N, and NH
4
+
/NO
X
were additional key environmental factors that influenced the anammox community diversity and distribution. This study yields a better understanding of the ecological distribution of anammox bacteria and the dominant genera in selective niche.
The temples of Angkor monuments including Angkor Thom and Bayon in Cambodia and surrounding countries were exclusively constructed using sandstone. They are severely threatened by biodeterioration ...caused by active growth of different microorganisms on the sandstone surfaces, but knowledge on the microbial community and composition of the biofilms on the sandstone is not available from this region. This study investigated the microbial community diversity by examining the fresh and old biofilms of the biodeteriorated bas-relief wall surfaces of the Bayon Temple by analysis of 16S and 18S rRNA gene sequences. The results showed that the retrieved sequences were clustered in 11 bacterial, 11 eukaryotic and two archaeal divisions with disparate communities (Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Proteobacteria; Alveolata, Fungi, Metazoa, Viridiplantae; Crenarchaeote, and Euyarchaeota). A comparison of the microbial communities between the fresh and old biofilms revealed that the bacterial community of old biofilm was very similar to the newly formed fresh biofilm in terms of bacterial composition, but the eukaryotic communities were distinctly different between these two. This information has important implications for understanding the formation process and development of the microbial diversity on the sandstone surfaces, and furthermore to the relationship between the extent of biodeterioration and succession of microbial communities on sandstone in tropic region.
We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH) enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP) compounds ...with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol). Briefly, MPH containing six sequential histidines (6× His tag) at its N-terminal was bound to nitrilotriacetic acid (NTA) agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs) and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP) concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications.
Wide-bandgap all-inorganic CsPbIBr 2 solar cells with MoO x /Ag/TeO 2 composite transparent electrode have been firstly used to construct a 4T perovskite/Si-heterojunction tandem cells. The ...calculation results showed that the long wavelength transmission (600 to 1100 nm) of MoO x /Ag film can be enhanced remarkably by adding a TeO 2 optical capping layer. This resulted in an obviously increase of the PCE (J SC ) from 10.70% (17.56 mA/cm 2 ) to 14.76% (24.67 mA/cm 2 ) for corresponding bottom Si cell in CsPbIBr 2 /Si devices, although the PCE of top CsPbIBr 2 cell decreased from 17.52% to 16.58%, the overall PCE of tandem device has increased from 28.22% to 31.34%. This J SC -dependent PCE improvement mainly came from the more balanced light absorption, which can be understood by the optical interference induced light field redistributions in CsPbIBr 2 /Si devices. Specially, comparing with the original Si cell, the J SC and PCE losses in bottom Si cell have been suppressed to about 33% and 32%, which are superior to most the reported pervoskite/Si tandem cells. Therefore, the tandem of Si cell and CsPbIBr 2 cell with optimized MoO x (20 nm)/Ag(8 nm)/TeO 2 (50 nm) transparent electrode could be the promising cost-effective photovoltaic in the future. This work is instructive to the fabrication of pervoskite/Si tandem solar cells.
All-inorganic carbon-based CsPbIBr2 perovskite solar cells (PSCs) have attracted increasing interest due to the low cost and the balance between bandgap and stability. However, the relatively narrow ...light absorption range (300 to 600 nm) limited the further improvement of short-circuit current density (JSC) and power conversion efficiency (PCE) of PSCs. Considering the inevitable reflectance loss (~10%) at air/glass interface, we prepared the moth-eye anti-reflector by ultraviolet nanoimprint technology and achieved an average reflectance as low as 5.15%. By attaching the anti-reflector on the glass side of PSCs, the JSC was promoted by 9.4% from 10.89 mA/cm2 to 11.91 mA/cm2, which is the highest among PSCs with a structure of glass/FTO/c-TiO2/CsPbIBr2/Carbon, and the PCE was enhanced by 9.9% from 9.17% to 10.08%. The results demonstrated that the larger JSC induced by the optical reflectance modulation of moth-eye anti-reflector was responsible for the improved PCE. Simultaneously, this moth-eye anti-reflector can withstand a high temperature up to 200 °C, and perform efficiently at a wide range of incident angles from 40° to 90° and under various light intensities. This work is helpful to further improve the performance of CsPbIBr2 PSCs by optical modulation and boost the possible application of wide-range-wavelength anti-reflector in single and multi-junction solar cells.
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