Amazonian Materials Group, Department of Physics, Federal University of Amapá-UNIFAP, Rod. Juscelino Kubitscheck, km 02 - Jardim Marco Zero, Macapá, Amapá 68.903-419, Brazil.
Department of Physiscs, Federal University of Alagoas-UFAL, Rodovia AL 145, Km 3, 3849 - Cidade Universitária, Delmiro Gouveia, Alagoas 57.480-000, Brazil.
Microscopy (Oxf). 2024 Feb 7;73(1):55-65. doi: 10.1093/jmicro/dfad040.
We conducted a comprehensive analysis of the surface microtexture of kefir biofilms grown on Theobroma grandiflorum Shum (cupuaçu) juice using atomic force microscopy. Our goal was to investigate the unique monofractal and multifractal spatial patterns of these biofilms to complement the existing limited literature. The biofilms were prepared dispersing four different concentrations of kefir grains in cupuaçu juice. Our morphological analysis showed that the surface of the obtained biofilms is essentially formed by the presence of cupuaçu fibers and microorganisms like lactobacilli and yeast. The topographic height-based parameter analysis reveals that there is a dependence between surface roughness and the concentration of kefir grains used. The strongly anisotropic well-centralized topographical height distribution of the biofilms also exhibited a quasi-symmetrical and platykurtic pattern. The biofilms exhibit comparable levels of spatial complexity, surface percolation and surface homogeneity, which can be attributed to their similar topographic uniformity. This aspect was further supported by the presence of similar multifractality in the biofilms, suggesting that despite their varying topographic roughness, their vertical growth dynamics follow a similar pattern. Our findings demonstrate that the surface roughness of kefir biofilms cultivated on cupuaçu juice is influenced by the concentration of kefir grains in the precursor solution. However, this dependence follows a consistent pattern across different concentrations. Graphical Abstract.
我们使用原子力显微镜对可可（cupuaçu）汁上生长的开菲尔生物膜的表面微观结构进行了全面分析。我们的目标是研究这些生物膜独特的单分形和多分形空间模式，以补充现有有限的文献。生物膜是通过将四种不同浓度的开菲尔粒分散在可可汁中制备的。我们的形态分析表明，获得的生物膜的表面基本上是由可可纤维和像乳杆菌和酵母这样的微生物的存在形成的。基于地形高度的参数分析表明，表面粗糙度与使用的开菲尔粒浓度之间存在依赖性。生物膜强烈各向异性的中心集中的地形高度分布也表现出准对称和扁态分布模式。生物膜表现出相当的空间复杂性、表面渗透和表面均匀性，这可以归因于它们相似的地形均匀性。这一方面进一步得到了生物膜中存在相似的多分形性的支持，这表明尽管它们的地形粗糙度不同，但它们的垂直生长动态遵循相似的模式。我们的研究结果表明，在可可汁上培养的开菲尔生物膜的表面粗糙度受到前体溶液中开菲尔粒浓度的影响。然而，这种依赖性在不同浓度下呈现出一致的模式。
