Microbiome Diversity and Cellulose Decomposition Processes by Microorganisms on the Ancient Wooden Seawall of Qiantang River of Hangzhou, China.

Archaeological wood, also known as wooden cultural relics, refers to ancient wood that has been worked by humans. Further insights into the decomposition mechanism of archaeological wood are needed for its preventive conservation. In this study, we assessed the microbiome diversity and cellulose decomposition processes on a 200-year-old ancient wooden seawall - the Qiantang River of Hangzhou, China. We used high-throughput sequencing (HTS) to deduce the metagenomic functions, particularly the cellulose-decomposing pathway of the microbial communities, through bioinformatical approaches. The predominant cellulose-decomposing microorganisms were then verified with traditional isolation, culture, and identification method. The results showed that the excavation of archaeological wood significantly altered the environment, accelerating the deterioration process of the archaeological wood through the carbohydrate metabolism and the xenobiotic biodegradation and metabolism pathways, under the comprehensive metabolism of complex ecosystem formed by bacteria, archaea, fungi, microfauna, plants, and algae. Bacteroidetes, Proteobacteria, Firmicutes, and Actinobacteria were found to be the predominant source of bacterial cellulose-decomposing enzymes. Accordingly, we suggest relocating the wooden seawall to an indoor environment with controllable conditions to better preserve it. In addition, these results provide further evidence for our viewpoints that HTS techniques, combined with rational bioinformatical data interpretation approaches, can serve as powerful tools for the preventive protection of cultural heritage.

An electrochemical immunosensor for the detection of carcinoembryonic antigen based on Au/g-C3N4 NSs-modified electrode and CuCo/CNC as signal tag.

Carcinoembryonic antigen levels in the human body reflect the conditions associated with a variety of tumors and can be used for the identification, development, monitoring, and prognosis of lung cancer, colorectal cancer, and breast cancer. In this study, an amperometric immunosensor with CuCo/carbon nanocubes (CuCo/CNC) as the signal label is constructed. The bimetal-doped carbon skeleton structure has a high specific surface area and exhibits good electrocatalytic activity. In addition, Au/g-C3N4 nanosheets (Au/g-C3N4 NSs) are used to modify the substrate platform, facilitating the loading of more capture antibodies. The reaction mechanism was explored through electrochemical methods, X-ray powder diffraction, X-ray photoelectron spectroscopy, and other methods. Kinetic studies have shown that CuCo/CNC have good peroxidase-like activity. In addition, the electrocatalytic reduction ability of CuCo/CNC on hydrogen peroxide can be monitored using amperometric i-t curve (- 0.2 V, vs. SCE), and the response current value is positively correlated with the CEA antigen concentration. The prepared electrochemical immunosensor has good selectivity, precision, and stability. The dynamic range of the sensor was 0.0001-80 ng/mL, and the detection limit was 0.031 pg/mL. In addition, the recovery and relative standard deviation in real serum samples were 97.7-103 % and 3.25-4.13 %, respectively. The results show that the sensor has good analytical capabilities and can provide a new method for the clinical monitoring of CEA.

Immunological Methods for the Detection of Binders in Ancient Tibetan Murals.

Tibetan mural samples from the Jiazhaer mountain cave were studied using enzyme-linked immunosorbent assays (ELISA) and immunofluorescence microscopy (IFM). Samples containing protein binders were first identified using ELISA, and then IFM was used to determine the location of protein binders. Using these methods, we discovered gelatin and casein in samples from wall murals, distributed in both red and black pigments. We excluded the possibility of contamination by conducting further experiments where simulated samples were spiked with milk. We conclude that both gelatin and casein were used as binders in the pigments of the Tibetan Buddhist murals in the Jiazhaer (Transliteration from Tibetan) mountain cave. This is the first evidence of casein being used as a binder in Chinese mural pigments.

Deterioration-Associated Microbiome of Stone Monuments: Structure, Variation, and Assembly.

Research on the microbial communities that colonize stone monuments may provide a new understanding of stone biodeterioration and microbe-induced carbonate precipitation. This work investigated the seasonal variation of microbial communities in 2016 and 2017, as well as its effects on stone monuments. We determined the bacterial and fungal compositions of 12 samples from four well-separated geographic locations by using 16S rRNA and internal transcribed spacer gene amplicon sequencing. Cyanobacteria and Ascomycota were the predominant bacterial and fungal phyla, respectively, and differences in species abundance among our 12 samples and 2 years showed no consistent temporal or spatial trends. Alpha diversity, estimated by Shannon and Simpson indices, revealed that an increase or decrease in bacterial diversity corresponded to a decrease or increase in the fungal community from 2016 to 2017. Large-scale association analysis identified potential bacteria and fungi correlated with stone deterioration. Functional prediction revealed specific pathways and microbiota associated with stone deterioration. Moreover, a culture-dependent technique was used to identify microbial isolates involved in biodeterioration and carbonatogenesis; 64% of 85 bacterial isolates caused precipitation of carbonates in biomineralization assays. Imaging techniques including scanning electron microscopy with energy-dispersive spectroscopy, X-ray diffraction, and fluorescence imaging identified CaCO3 crystals as calcite and vaterite. Although CaCO3 precipitation induced by bacteria often has esthetically deleterious impacts on stone monuments, this process may potentially serve as a novel, environmentally friendly bacterial self-inoculation approach to the conservation of stone.IMPORTANCE Comprehensive analyses of the microbiomes associated with the deterioration of stone monuments may contribute to the understanding of mechanisms of deterioration, as well as to the identification of potentially beneficial or undesirable microbial communities and their genomic pathways. In our study, we demonstrated that Cyanobacteria was the predominant bacterial phylum and exhibited an increase from 2016 to 2017, while Proteobacteria showed a decreasing trend. Apart from esthetic deterioration caused by cyanobacteria and fungi, white plaque, which is composed mainly of CaCO3 and is probably induced by Crossiella and Cyanobacteria, was also considered to be another threat to stone monuments. We showed that there was no significant correlation between microbial population variation and geographic location. Specific functional genes and pathways were also enriched in particular bacterial species. The CaCO3 precipitation induced by an indigenous community of carbonatogenic bacteria also provides a self-inoculation approach for the conservation of stone.

Role of Fungi in the Formation of Patinas on Feilaifeng Limestone, China.

Feilaifeng is a cultural heritage site that contains unique Buddhist statues which date back to the Five Dynasties period (907 AD-960 AD). The site was inscribed on world heritage list by UNESCO in 2011. Various patinas, which may be caused by fungi, have covered the surface of the limestone and have severely diminished the esthetic value of the statues and altered the limestone structure. Culture-dependent method was used to isolate and identify the fungi. After incubation on modified B4 medium, the calcifying fungi were identified by optical microscopy and scanning electron microscopy combined with X-ray energy-dispersive analysis. Aspergillus, Penicillium, and Colletotrichum were observed as the biomineralizing fungi. X-ray diffraction showed that the patina consisted of calcite (CaCO3), but the crystals synthesized by the identified fungi were whewellite (CaC2O4·H2O) for Aspergillus and Penicillium, and vaterite (CaCO3) for Colletotrichum. In addition, the metabolites of Colletotrichum suppressed the transformation of vaterite to calcite, but Mg2+ could inhibit the function of the metabolites. The different crystal form between the patina and the products of fungi may suggest two different pathways of patina formation and provide important reference data for studies of the mechanisms of biomineralization, cleaning of the patina, and protection of the Feilaifeng statues.

An Adaptive Prediction Target Search Algorithm for Multi-AUVs in an Unknown 3D Environment.

For a target search of autonomous underwater vehicles (AUVs) in a completely unknown three-dimensional (3D) underwater environment, a multi-AUV collaborative target search algorithm based on adaptive prediction is proposed in this paper. The environmental information sensed by the forward-looking sonar is used to judge the current state of view, and the AUV system uses this environmental information to perform the target search task. If there is no target in the field of view, the AUV system will judge whether all sub-regions of the current layer have been searched or not. The next sub-region for searching is determined by the evaluation function and the task assignment strategy. If there are targets in the field of view, the evaluation function and the estimation function of the adaptive predictive optimization algorithm is used to estimate the location of the unknown target. At the same time, the algorithm also can reduce the positioning error caused by the noise of the sonar sensor. In this paper, the simulation results show that the proposed algorithm can not only deal with static targets and random dynamic interference target search tasks, but it can also perform target search tasks under some random AUV failure conditions. In this process, the underwater communication limits are also considered. Finally, simulation experiments indicate the high efficiency and great adaptability of the proposed algorithm.

Microchemical Study of Pigments and Binders in Polychrome Relics from Maiji Mountain Grottoes in Northwestern China.

In this study, an integrated analytical method was developed to investigate the composition of both the inorganic pigments and organic binders of polychrome relics in Maiji Mountain Grottoes in northwestern China. Cross-sections of each sample were prepared at the beginning of the study, and all experiments were carried out on these cross-sections. Polychromic structures were revealed by optical microscopy and scanning electron microscopy-backscattered electron imaging. Inorganic materials were determined by using SEM coupled with an energy dispersive spectrometer and µ-Raman spectrometer, whereas organic materials were identified by staining techniques and highly sensitive and specific immunofluorescence microscopy. Data showed that the red colors are attributed to one or two pigments of red ochre, cinnabar, and minium; the blue pigment is natural lazurite; the green pigment is ascribed to atacamite; the white color is attributed to potassium feldspar; and the black surface is formed by the discoloration of minium to plattnerite under the influence of environmental factors. Regarding organic binders used in painting and preparation layers, mammalian animal glue and chicken egg white were both found alone or in mixture. Finally, the conclusion is made that the Secco technique is employed in polychrome relics from Maiji Mountain Grottoes.

[The Analysis of Traditional Lime Mortars from Zhejiang Province, China].

The components of ancient mortars have always been an important research field in historic building conservation. It has been well known that using traditional mortars in conservation projects have many advantages, such as compatibility and stability. So, developing new binding materials based on traditional mortar has become an international study hotspot. With China's economic development, the protection of ancient buildings also began to put on the agenda, but the understanding on Chinese traditional mortar is limited, and rare literatures are reported. In the present work, the authors investigate seven ancient city wall sites in Zhejiang Province in situ, and subsequently laboratory analysis were carried out on collected mortar samples. The characterizations of mortar samples were made by multi-density gauge, XRD, FTIR, TG-DSC and wet chemical analysis. The experimental results showed that: the main component of masonry mortars is calcium carbonate, the content between 75% - 90%, and they should be made from relatively pure lime mortar. The raw materials of mortar samples were mainly calcareous quick lime, and sample from Taizhou city also contained magnesium quick lime. There are four city walls were built by sticky-rice mortars. It suggests that the technology of adding the sticky rice soup into mortar was universal in the Ming Dynasties. These mortars have lower density between 1.2 and 1.9 g x cm(-3); this outcome should be the result of long-term natural erosion. We have also analyzed other chemical and physical characteristics of these masonry mortars. The results can afford the basic data for the future repairmen programs, development of new protective materials, and comparative study of mortars.

Identification of Organic Binders in Ancient Chinese Paintings by Immunological Techniques.

The identification and localization of organic binders in artworks are big challenges in archaeology and conservation science. Immunological techniques, such as enzyme-linked immunosorbent assay (ELISA) and immunofluorescence microscopy (IFM) have the potential to become powerful tools for the analysis of organic materials in ancient samples. In this study, ELISA and IFM techniques were combined to identify chicken ovalbumin, glue from several mammalian species, bovine milk, and fish glue in ancient Chinese painting samples. As binders, egg ovalbumin was found in two painting samples and animal glue was found in three samples, which were dated from the 4th to 8th centuries. The results clearly demonstrate that ELISA and IFM can be used to validate results from ancient samples.

[Study on Archaeological Lime Powders from Taosi and Yinxu Sites by FTIR].

Archaeological lime powders samples from Taosi and Yinxu sites, natural limestone and experimentally prepared lime mortar were investigated by means of Fourier transform infrared spectrometry (FTIR) to identify the raw material of lime powders from Taosi and Yinxu sites. Results show that ν2/ν4 ratio of calcite resulted from carbonation reaction of man-made lime is around 6.31, which is higher than that of calcite in natural limestone and reflects the difference in the disorder of calcite crystal structure among the natural limestone and prepared lime mortar. With additional grinding, the values of v2 and ν4 in natural limestone and prepared lime mortar decrease. Meanwhile, the trend lines of ν2 versus ν4 for calcite in experimentally prepared lime mortar have a steeper slope when compared to calcite in natural limestone. These imply that ν2/ν4 ratio and the slope of the trend lines of ν2 versus ν4 can be used to determine the archaeological man-made lime. Based on the experiment results, it is possible that the archaeological lime powder from Taosi and Yinxu sites was prepared using man-made lime and the ancient Chinese have mastered the calcining technology of man-made lime in the late Neolithic period about 4 300 years ago.

Application of ELISA in Cultural Heritage: Recent Advances and Challenges.

Organic residue analyses have long been the primary focus and challenge in the fields of scientific archaeology and cultural heritage. Enzyme-linked immunosorbent assay (ELISA) has emerged as a valuable method for detecting organic residues owing to its high sensitivity and specificity. Organic components have been observed within four categories of archaeological artifacts: mortars, adhesives, animal and plant remains, and daily use artifacts. Therefore, in this article, we critically analyzed the advantages and limitations of ELISA in detecting organic residues by tracking its recent application in the abovementioned categories. The current focus of ELISA applications is on the preparation of customized antibodies, development of multicomponent detection methods, and meeting on-site identification demands. Additionally, understanding organic residue degradation mechanisms and the proper handling of archaeological samples are also key factors in these applications. Integration of ELISA with biomolecular science and electrochemistry has allowed the development of comprehensive detection and analyses. In the future, ELISA will be capable of handling more complex and diverse analyses, revealing highly intricate information from archaeological samples.

Activity-based protein profiling technology reveals malate dehydrogenase as the target protein of cinnamaldehyde against Aspergillus niger.

Cinnamaldehyde displays strong antifungal activity against fungi such as Aspergillus niger, but its precise molecular mechanisms of antifungal action remain inadequately understood. In this investigation, we applied chemoproteomics and bioinformatic analysis to unveil the target proteins of cinnamaldehyde in Aspergillus niger cells. Additionally, our study encompassed the examination of cinnamaldehyde's effects on cell membranes, mitochondrial malate dehydrogenase activity, and intracellular ATP levels in Aspergillus niger cells. Our findings suggest that malate dehydrogenase could potentially serve as an inhibitory target of cinnamaldehyde in Aspergillus niger cells. By disrupting the activity of malate dehydrogenase, cinnamaldehyde interferes with the mitochondrial tricarboxylic acid (TCA) cycle, leading to a significant decrease in intracellular ATP levels. Following treatment with cinnamaldehyde at a concentration of 1 MIC, the inhibition rate of MDH activity was 74.90 %, accompanied by an 84.5 % decrease in intracellular ATP content. Furthermore, cinnamaldehyde disrupts cell membrane integrity, resulting in the release of cellular contents and subsequent cell demise. This study endeavors to unveil the molecular-level antifungal mechanism of cinnamaldehyde via a chemoproteomics approach, thereby offering valuable insights for further development and utilization of cinnamaldehyde in preventing and mitigating food spoilage.

The relationship between the microclimate and efflorescence of revealed mural paintings and the later protection strategy.

Throughout history, there were many fine mural paintings concealed within ancient buildings, hidden beneath layers of plaster, wall or other structure. In recent decades, research and practical efforts had primarily focused on nondestructive diagnosis of these hidden murals and the removal of their surface coverings. However, limited attention had been given to the consequences of overlay removal on mural preservation. This study aims to address this gap by examining the revealed mural paintings in the Prince Shi's Palace as a case study, employing an analysis of mural ontology, investigation into the preservation environment, and simulation experiments to comprehensively analyze the factors contributing to the rapid deterioration of these revealed murals. The findings indicated that certain carbonated lime particles adhered to the mural surface, and in a humid environment, these particles absorbed sulfur dioxide from the atmosphere and converted into calcium sulfate. The strong hygroscopic property of calcium sulfate enhanced the humidity on the surface of murals, thereby increasing their susceptibility to sulfur dioxide absorption. Over time, the murals suffered more sulphate and moisture damage. Additionally, historically inaccurate interventions such as non-breathable shading curtains installation and organic coatings reinforcement exacerbated this deterioration process. Therefore, safeguarding the integrity of these exposed concealed murals necessitated prioritizing the preservation of environmental humidity and acid gas levels.

[Study on the traditional lime mortar from the memorial archway in the southern Anhui province].

The traditional lime mortar was investigated by means of scanning electron microscope (SEM), X-ray diffractometry and Fourier transform infrared spectrometry (FTIR). The results show that the mortar from the memorial archway in the southern Anhui province was the organic-inorganic composite materials composed of lime with tung oil or sticky rice. It was found that the excellent performance of the tung oil-lime mortar can be explained by the compact lamellar organic-inorganic composite structure that was produced by carbonization reaction of lime, cross-linking reactions of tung oil and oxygen and complexing reaction of Ca2+ and -COO-. The compact micro-structure of sticky rice-lime mortar, which was produced due to carbonation process of lime controlled by amylopectin, should be the cause of the good performance of this kind of organic-inorganic mortar.

A portable microfluidic device integrated with electrochemical sensing platform for detection of multiple binders in ancient wall paintings.

The aging of the proteinaceous binders will cause the cultural relics to suffer from diseases such as flaking, cracks, and even peeling. Identifying the type of binders in a timely manner is conducive to restore diseased cultural relics. High-throughput and portable detection system are of great significance for researching cultural relic materials on the archaeological site. Therefore, in this work, a portable electrochemical microfluidic device for the simultaneous detection of casein, ovalbumin, and peach gum binders was developed. The proposed electrochemical immunosensor technology integrated with microfluidic device achieve the goals of miniaturization, portability and reagent-saving. For casein, ovalbumin and peach gum, excellent performance was obtained in terms of their limits of detection (LOD) at 0.237, 0.507, and 0.403 ng mL-1 (S/N = 3), respectively. In addition, the microfluidic sensing platform exhibited acceptable anti-interference ability, stability, and storage capacity. In order to evaluate the practical application value, the proposed microfluidic sensing device was applied for detecting eight archaeological samples from different historic sites. This work demonstrates great potential for high-throughput, portable detection of cultural relic proteinaceous binder materials.

Dynamics of microbial community composition during degradation of silks in burial environment.

The silk residues in the soil formed the unique niche, termed "silksphere." Here, we proposed a hypothesis that silksphere microbiota have great potential as a biomarker for unraveling the degradation of the ancient silk textiles with great archaeological and conservation values. To test our hypothesis, in this study, we monitored the dynamics of microbial community composition during silk degradation via both indoor soil microcosmos model and outdoor environment with amplicon sequencing against 16S and ITS gene. Microbial community divergence was evaluated with Welch two sample t-test, PCoA, negative binomial generalized log-linear model and clustering, etc. Community assembly mechanisms differences between silksphere and bulk soil microbiota were compared with dissimilarity-overlap curve (DOC) model, Neutral model and Null model. A well-established machine learning algorithm, random forest, was also applied to the screening of potential biomarkers of silk degradation. The results illustrated the ecological and microbial variability during the microbial degradation of silk. Vast majority of microbes populating the silksphere microbiota strongly diverged from those in bulk soil. Certain microbial flora can serve as an indicator of silk degradation, which would lead to a novel perspective to perform identification of archaeological silk residues in the field. To sum up, this study provides a new perspective to perform the identification of archaeological silk residue through the dynamics of microbial communities.

[Study on the mechanism of liesegang pattern development during carbonating of traditional sticky rice-lime mortar].

Liesegang patterns in traditional sticky rice-lime mortar undergoing carbonation were investigated by means of FTIR, XRD and SEM. Results indicate that well-developed Liesegang patterns only occur in the mortar prepared with aged lime and sticky rice. The smaller Ca(OH)2 particle size in aged lime and the control of the sticky rice for the crystallization of calcium carbonate lead to the small pores in this mortar. These small pores can make Ca2+ and CO3(2-) highly supersaturated, which explains the reason why Liesegang pattern developed in the sticky rice-aged lime mortar. The formed metastable aragonite proves that Liesegang pattern could be explained based on the post-nucleation theory.

Phosphonium-based ionic liquids as antifungal agents for conservation of heritage sandstone.

With a view to preventing fungal deterioration of historical stone artworks, we report the use of phosphonium-based ionic liquids (ILs) as potent antifungal agents against dematiaceous fungi commonly found on heritage stones. Three ILs: tributyldodecylphosphonium polyoxometalate [P44412][POM], tributyltetradecylphosphonium polyoxometalate [P44414][POM], and trihexyltetradecylphosphonium polyoxometalate [P66614][POM] were prepared and their thermal stabilities and in vitro antifungal activities were evaluated. From the ramped temperature thermogravimetric analysis and antifungal experiments it can be clearly observed that the alkyl chain length of the tetraalkylphosponium cation has a significant influence on the thermal and antifungal properties. The thermal stability and antifungal activity decreased as the number of carbon atoms of the alkyl substituents increased and, thus, followed the order [P44412][POM] > [P44414][POM] > [P66614][POM]. In addition, inoculation of four fungal species on IL-coated sandstone surfaces showed significant inhibition of fungal growth, endowing the materials with potential applications in heritage sandstone conservation.

Fabrication of a novel electrochemical immunosensor for the sensitive detection of carcinoembryonic antigen using a double signal attenuation strategy.

Carcinoembryonic antigen (CEA), an acidic protein, is a characteristic antigen produced by the tumor of various cancers (eg, breast, cervical, rectal, lung, etc.). Therefore, the detection of cancer antigens is very important for the early diagnosis and treatment of cancer. In this study, a novel of "signal off" strategy for electrochemical immunosensor was developed to detect CEA. To this end, Prussian blue nanoparticles (PB NPs), an electroactive substance, were used as the immunological platform. In addition, CuO2@SiO2 nanocomposites, which release Cu2+ and H2O2 under acidic conditions, were synthesized. The generated Cu2+ can replace the high spin iron (FeIII) in PB NPs, which in turn reduces the oxidation peak current of PB NPs. Due to the peroxidase-like nature of PB NPs, they can react with self-generated H2O2 to generate hydroxyl radicals (·OH), which can further convert 4-chloro-1 naphthol (4-CN) into a non-conductive polymer that accumulates on the electrode surface, this leads to a further reduction in the electrical signal of the PB NPs. Moreover, the self-generated Cu2+ and H2O2 can reduce the introduction of exogenous substances and improve the detection accuracy. Square wave voltammetry (SWV) revealed that the electrical signal of PB NPs gradually decreased with increasing CEA concentration. In addition, the electrical signal of PB NPs exhibited a good linearity in the range from 0.01 pg mL-1 to 80 ng mL-1, where in the logarithm of CEA concentration and the detection limit was as low as 0.0032 pg mL-1.

Study of sticky rice-lime mortar technology for the restoration of historical masonry construction.

Replacing or repairing masonry mortar is usually necessary in the restoration of historical constructions, but the selection of a proper mortar is often problematic. An inappropriate choice can lead to failure of the restoration work, and perhaps even further damage. Thus, a thorough understanding of the original mortar technology and the fabrication of appropriate replacement materials are important research goals. Many kinds of materials have been used over the years in masonry mortars, and the technology has gradually evolved from the single-component mortar of ancient times to hybrid versions containing several ingredients. Beginning in 2450 BCE, lime was used as masonry mortar in Europe. In the Roman era, ground volcanic ash, brick powder, and ceramic chip were added to lime mortar, greatly improving performance. Because of its superior properties, the use of this hydraulic (that is, capable of setting underwater) mortar spread, and it was adopted throughout Europe and western Asia. Perhaps because of the absence of natural materials such as volcanic ash, hydraulic mortar technology was not developed in ancient China. However, a special inorganic-organic composite building material, sticky rice-lime mortar, was developed. This technology was extensively used in important buildings, such as tombs, in urban constructions, and even in water conservancy facilities. It may be the first widespread inorganic-organic composite mortar technology in China, or even in the world. In this Account, we discuss the origins, analysis, performance, and utility in historic preservation of sticky rice-lime mortar. Mortar samples from ancient constructions were analyzed by both chemical methods (including the iodine starch test and the acid attack experiment) and instrumental methods (including thermogravimetric differential scanning calorimetry, X-ray diffraction, Fourier transform infrared, and scanning electron microscopy). These analytical results show that the ancient masonry mortar is a special organic-inorganic composite material. The inorganic component is calcium carbonate, and the organic component is amylopectin, which is presumably derived from the sticky rice soup added to the mortar. A systematic study of sticky rice-lime mortar technology was conducted to help determine the proper courses of action in restoring ancient buildings. Lime mortars with varying sticky rice content were prepared and tested. The physical properties, mechanical strength, and compatibility of lime mortar were found to be significantly improved by the introduction of sticky rice, suggesting that sticky rice-lime mortar is a suitable material for repairing mortar in ancient masonry. Moreover, the amylopectin in the lime mortar was found to act as an inhibitor; the growth of the calcium carbonate crystals is controlled by its presence, and a compact structure results, which may explain the enhanced performance of this organic-inorganic composite compared to single-component lime mortar.